Don't you love it when people offer to sell something & give you the "make offer" BS? I'd offer no more than $200 for the '86...it doesn't look like it's worth having...especially if there's no paperwork (how will you get rid of it?). Something to think about... Besides, you really don't know how much life's left in the transmission -- looking at the overheated modded/rigged up motor & the car in general, you know it's been abused....
Does the '85 have a title? If the car is rust free (check floorpans too) & has a title, I'd offer around $350. I'd go up to around $500 for it since I like TPI cars & probably restore it since it's a TPI car but everybody's different.
Finding unmolested/modded TPI cars is becoming harder & harder these days, at least for me anyway. They may never be worth much, but they're a blast to drive & they're good-looking too -- damn, even the engines are beautiful.
For the '85 consider the condition of: ..underbody rust, door hinges (they are welded to the doors & super-expensive to fix), dash pad (getting pricey), windshield. Expect to spend a weekend changing out the probably dead fuel pump...
Bottom line is....these things aren't scarce right now, so if you can't get it cheap, keep looking elsewhere.
For example, I gave $350 for my black '87 TPI T/A from a car dealer -- it was a repo & had a bad engine. I towed it home, put a battery in it, & have been driving it around for about four years. Probably got about $750 in it total.
Good luck!!