that's not an 86, look for a PV on it, axle is a dead give away as well as the pipe and seat.
87-90 is my guess by the pix. far as the banshee. eh, parts bike. like awk said, check compression on both. if shee is gone, offer him $800 and tell him it's enough to get a cr125 lol.
here's what I did when I got my pitbike and mini chopper, was not premeditated however, went to the guys house, checked them out (wife was supposed to bring half the money so I only had half) told him I only had half, but he didn't want me messing with them much and said he was really in a hurry, so I told him I can come back some other time. he told me give him the half and I can meet him the next day with the rest. I took the bikes and went home to immediately wrench/trouble shoot. problems went much deeper than he let on, so I called to ask if I could just get my money back and he never called back or answered. I left a few messages and ended up keeping the bikes and getting them both running and almost tripling my money lol after $ in parts ect.
so, go in with $1000 max tell him it was all you could swing atm and you can get the rest, then call him the following day and say both cyls in the shee have bad compression and see if he'll give u a refund LOL. more than likely he'll let you keep um both