4 or 5 years ago I made the mistake of selling a nice set to a guy I pulled off a junk machine and I sold those for $100 for the set. As you would expect they sold instantly. I say I made a mistake selling them for two reasons the first reason was I sold them way too cheap but more importantly I have needed two sets since and have never found any at any price.
In my eyes - if they are near perfect the 4 buildings with ramps should be worth close to $100 each to the right buyer. My price is based just on how hard they are to find. The center building without ramp is basically worthless - they are everywhere for under $25 and I have tried selling them for as little as $10 with no luck.
I know some people will say I am crazy saying the other 4 buildings are worth $400 for the lot but show me where you can find them at any price!