Topetoro
If you want to file a lawsuit check the CM/ECF for a good lawyer. Registration is very cheap 8c per page. But only a lawyer with some cases in the past several years might have a chance. If you go carefully thru all the files in the listed website in your message, you'll see that some of the lawsuits are unsuccesful. Second thing is that the lawsuit does not give you a visa, but only "pushes" eventually CIS to expedite the security check. This is what they call "in writ mandamus". If FBI cannot expedite it for some reasons , then you are in a trap, you cannot win the lawsuit, the court will make a non-favorable decision.
And $5000 and more seems about right for that kind of lawsuit. $2000 is a very small amount and I wouldn't even go with this lawyer. Not that the bigger amount - the greater lawyer, but you know "if it is that cheap, there will be something fishy"
Anyways wish you luck! I cannot imagine the suffering that you guys are going thru.