Can't speak for John, but I purchased a 1977 C150M last summer. Standard VFR package, very clean in and out. Only 3600 total time, 375 SMOH. STOL kit (not something I would have done, but the previous owner loved it). 1 year as a trainer (best I can tell). I paid between $20K and $25k. Probably paid to much but plane was close so I did not have any cost to go get plane and bring it home.
Seriously looked at three other 150's before buying 63U. Two were in bad shape and they were asking $22k to $23k for them. Don't know if they have been sold but I don't think they will get more than $18k for either one of them. Neither seller would budge on their price, even after I showed them a much nicer plane in their price range. And I had cash in hand and told them I was going to buy a plane from somebody.
Third plane was a SparrowHawk. Found out it had been crashed twice, once into the trees. I was not interested in plane with a lot of damage history, so seller and I never got serious. He was asking $25.5k. Plane was a little rough but was 125hp.
Followed for sale sites while I was looking. Less than good 150s do not seem to move quickly. Nice clean 150s that are reasonably priced do not seem to stay on the market long.
I think I could have gotten a better deal if I would have held out and looked at more planes. But I was burning money renting while I was looking.
Only my observations while I was buying my 150. Lot of high time, original paint and interior 150s out there. But nice clean 150s are getting harder to come by.
Just my opinions.
I listed my 150 on a free Controller ad and also a free 25 character no picture Barnstormers ad and no kidding had 4 serious buyers within 3 days. Scheduling the current annual for the buyer etc took a few weeks to get completed and during that time I turned down buyers begging me to take their cash and back out on pending buyer etc. One guy offered me $26,000 with the exsisting march 2013 annual but I declined since I gave the first guy my word etc. I truley believe someone would wind up giving closer to $30k for that plane in upcoming years from the response I received