For example, if I buy a pirated copy of a North American book from a local market in Bangladesh, can the publisher sue me and the seller? I can attempt to buy original copies of the book; however, they are extremely expensive and the book will take about 30-60 days to reach me.
Each country has its own copyright law, but the majority of countries have signed the Berne Copyright Convention, and most of those that have not, have joined the TRIPS agreement, which includes most of the same provisions. See Wikipedia for a list of those countries that do not adhere to Berne. Bangladesh is not on the list.
The Berne Copyright Convention specifies the basics of copyright protection, requires a minimum term of protection, requires that copyright be granted without any formalities such as a copyright notice or registration, and requires that authors from other signatory countries be given at least as much protection as authors from the current country. It leaves many details to local law, however, including what exceptions to copyright are allowed.
However, the Berne Convention does not require that buying a work that infringes copyright be treated as infringement, and I do not know of any country where it is, although I do not know the details of copyright law in Bangladesh
In the united-states the copyright owner has the right to make or authorize the making of copies and to distribute or authorize the distribution of such copies. But once an authorized copy has been sold, the owner of the copy may re-sell it, lend it, or give it away to anyone, and no permission from the copyright owner is required. In the US this is called the "First Sale Doctrine". The laws of many other countries, including the EU countries and the UK, are similar in this regard.
That means that it is perfectly legal to take lawfully created and purchased copies into another country and resell them there.
Moreover, if someone makes a copy without permission, or knowingly distributes such a copy, that person commits copyright infringement, and could in theory be sued, but the buyer does not.
It should be noted that under US law the First Sale Doctrine does not apply to unauthorized (pirated) copies. It is copyright infringement to knowingly sell (but not to buy) unauthorized copies under US law, and it is an infringement to re-sell such copies if the seller knows that they are unauthorized, although at a private sale this is not likely to be enforced.
The Copyright law of Bangladesh is somewhat different. Section 71 (in chapter 13) provides that infringement occurs:
(a) when any person, without a license ... or in contravention of the conditions of a license ...
(a)(i) does anything, the exclusive right to do which is by this Act conferred upon the owner of the copyright; ...
(b) When any person-
(b)(i) makes for sale or hire, or sells or lets for hire, or by way of trade displays or offers for sale or hire, or
(b)(iv) imports into Bangladesh, any infringing copies of the work.
The "exclusive rights" are given in section 14(1) of the same act (part of chapter 3) The relevant ones are:
(a) to reproduce the work in any material form including the storing of it in any medium by electronic means;
(b) to issue copies of the work to the public except copies already in circulation;
At the end of section 14, it is noted that:
For the purposes of this section, the copy which has been sold once shall be deemed to be a copy already in circulation.
This seems to be the Bangladesh version of the First Sale Doctrine, and it does not, at least not explicitly, contain the same rule as US law does, that to see or rent an unauthorized copy is infringement, even if there was a previous sale. But such a rule may have been imposed by caselaw.
So a copy of a book (or any other protected work) purchased in Bangladesh might or might not have been properly authorized, but the purchaser is not committing infringement in either case.
Section 74 of the Bangladesh copyright act does provide that
⎯(1) The Registrar, [may] ... order that copies made out of Bangladesh of the work which if made in Bangladesh would infringe copyright shall not be imported.
(2) ... the Registrar or any person authorized by him in this behalf may enter into any air-craft, ship, vehicle, dock or premises where any such copies ... may be found and may examine such copies.
(3) All copies to which any order made under sub-section (1) applies shall be deemed to be goods of which the bringing into Bangladesh has been prohibited or restricted under section 16 of the Customs Act, 1969, (Act IV of 1969) and all the provisions of said Act shall have effect accordingly
This appears to permit the seizure of improperly imported copies, but not prosecution of a purchaser of such copies. Whether it would be likely to be enforced in the case of copies sold in a street market I could not guess.
Moreover, it is unlikely that a publisher will find it worth its while to sue a street market seller, even if that person sells a clearly pirated copy of a book, particularly in a foreign country (foreign to the publisher, that is). The publisher or copyright owner probably could sue, depending on the details of the law in the country where the sale occurs. But the suit would have to be brought in the courts of that country, and might well cost more to bring than any plausible damage award would yield. Still some copyright owners might sue if they learn of such a sale. But the buyer is not at risk unless the law in the country where the sale takes place is different from that of most countries in this matter.
With reference to the law of Bangladesh, you are probably safe from legal action: see Chapter 13, which defines infringement in terms of making unpermitted copies, not acquiring them. Under §79, your copy can be taken, but there is no statutory provision for penalizing you for possession of an infringing copy. Since Bangladesh is a common law regime, there is a theoretical possibility that you could be held liable for contributory infringement, but that would depend on what the courts of Bangladesh have rules on that subject, and there is no evidence that they have "created" a legal remedy against the purchaser.
Copyright is international
Bangladesh copyright system "has resulted from the British Copyright System and the Copyright Ordinance that was promulgated by the amalgamation of different Copyright Laws in 1962. After the administration of this Ordinance up to 1999, the Copyright Act was enacted in 2000 and amended in 2005."
"Bangladesh became a legal member of the Paris Convention for the Protection of Industrial Property and of the Berne Convention for the Protection of Literary and Artistic Works in 1991 and 1999 respectively."
All the above together, copyright binds in Bangladesh as in North America.
On the other hand, you cannot be expected to be a single person law enforcement. If you make a legal purchase, you don't go some back corner to get a thing, the seller is in public and you may reckon that known to law enforcement (as a shop in a city center), the purchase is legal, and a legal copy is the object of tender, the responsibility is on the seller.
I do not quite understand, if you mean you purchased a copy and it turned out illegal, or piracy was the intent? Then, you'd be stealing from the author, together with the seller.
If books are too expensive in Bangladesh, you need to change the economy. : )
Seriously, it is a very important symptom of a failing economy.