One element not touched on so far is the time and effort it takes for courts to support people who are representing themselves.
In England & Wales we have had significant problems with an increase in the number of "Litigants in Person" since deep cuts were made to Legal Aid. This has resulted in hearings taking longer, Lawyers and Judges time being wasted, court costs increasing, and people not getting the justice they deserve.
From Legal aid: how has it changed in 70 years?:
Under Laspo†, large areas of civil legal aid were deemed out of scope and removed entirely from any legal aid coverage. These included most cases involving housing problems, family law, immigration, employment disputes and challenges to welfare benefit payments. The family courts, in particular, have been inundated with unrepresented defendants: about 80% of cases involve at least one side being unrepresented.
† Legal Aid, Sentencing and Punishment of Offenders Act
It has been suggested that the total cost, to society, of Legal Aid cuts may be significantly higher than the savings made from those cuts.
From Legal aid cuts are a false economy:
In 2010 Citizens Advice estimated that for every £1 spent spent on legal aid, the State saves :£2.34 from housing advice; £2.98 from debt advice; £8.80 from benefits advice; and £7.13 from employment advice.
Similarly from Benefits of legal aid significantly outweigh costs, according to global study:
A study in the U.S. State of Kentucky found that for every $1 spent on a civil protective order, there were $32 in avoided costs for society. A similar study in the state of Wisconsin estimated that the net economic benefits of expanding the domestic violence legal aid programme amounted to $9.8 million.
Lawyers spend their days (and often their nights) understanding the nuance of the Law, and working out ways of presenting those nuances in such a way that they can be quickly and efficiently understood by all.
Without legal grease, the wheels of justice would grind to a halt.
Oh, and to paraphrase Lincoln:
A lawyer who represents themself has a fool for a client