I checked actual cost. It is just under $400 per month for one license. Here is a cost breakdown if you want some things a la cart and others blanket license. They are a LOT of money and are cost prohibitive unless they are used as a part of your legal practice. That said, everything available on Lexis or Westlaw are available at other, free sites. If you are looking for state and federal statutes, as well as precedent setting cases, those can be found on Findlaw (and other similar sites). Each state also publishes all of their statutes online, as well as law court decisions. The same is true of statutes and legislation. Legislative history can be obtained at any law library. These places also have free access to West and Lexis on their public computers. So they charge a premium for the convenience of having everything in one spot, as well as a variety obtain of other services that wouldn't be relevant to lay persons (like Accurint).
I should amend to say Lexis/West does have things that you cannot just get online such as treatises practice guy, forms, etc. What I meant when I said that you can get pretty much everything for free online was statutes, case law, regs, etc.