First off, its a nice car. Except for the hardtop (didn't know they made a ZX hartop) and the 2+2 ( i presonally think they look much uglier, and they are heavier, though not much). I have an 82 280ZX, and finding parts for them in a junkyard is one of the easiest things ever. Unless its a turbo
Anyway, i think that you should pay the money. I dont think this is a fight worth fighting just because of the principles. You knew they didn't have the title for it when you bought it. You knew they would have to try and get it. You dont have any idea, however, how much it cost them to get it. It very well may have cost twice that to get records from the DMV, track it down, get copies and do all the legal work. They could have told you "We cant find or do anything about the title. You're on your own to track it down". In which case im sure you would have gladly paid 60 bucks for someone else to find it and deal with all the legalities.
In the end, it pay it and chalk it up to labor costs. i think its worth it, though they probably should have told you about the possible cost earlier, and you should have inquired about teh costs to get the title.