I would say the Amigo is worth about 3500 being generous...
If the Caballero is un molested and rust free I would say between 4 and 5 grand. The problem is that the eighties cars are not quite old enough to be a classic and not new enough to be sporty to alot of people. Its rareness is also what makes it a little harder sell. I have seen similar cars sell in the 2500 range but they had more miles and were not quite as clean. If it was me I would ask 4800 or maybe 5000 and go from there. In this market you would be more likely to trade for something you could use instead of selling. NADA value applies more to Barrett Jackson than RacingJunk or the front yard. I usually cut it in half.
I am not the worlds best wheeler dealer, but I sell and trade more than most people.
I hope this is helpful, I do not mean to offend, just be helpful if I can.