im not sure hed get 15 for any as they sit, but around here we look for southern cars like that. they could all be really solid. that roadrunner has ralleys on it. could be highly optioned. they just look dirty, only real damage i see is the dent on the 68s drivers fender and rear quarter which is an easy fix, and whatever top damamge on teh pass side of the rear edge of cuda hood. dont see the typical crusty wheel wells and bubbling rocker. if they are complete numbers matching cars, especially 4 speeds, or higher optioned, they could be easy projects with a big ROI. change anything rubber and dried out, maybe some mystery oil, they could fire up. its entirely possible you steam clean that roadrunner, and have beautiful original paint underneath that just needs a buff. if this guys took the tiome to steam clea all these cars hed have much better luck getting what he wants for them, but as they sit, they look like junk and probably wont get any bites.
i bought what i thought was a total p.o.s. 86 monte carlo ss once for 300 bucks. had that same 20 years of living under a tree crap all over it. but it was on a patio not grass. that tree junk steam cleaned off, quick buffing and i had a perfect burgundy paint job. change the belts and vac lines power washed underside, and it ran great, flipped it for 5k only spent 30 bucks on cleaning supplies and rubber parts, and a 50 dollar steam cleaner rental.
if any ones near by and can go inspect them, a full report would be great, full condition/damage, whats missing, and fender tag info on each.