First of all that machine is nice, very nice. I would still pursue it.
Most sellers don't care justifying a non working compressor for a lower price. As for as you continuing to look for another, it could be a while before one that nice pops up again and if it does I can guarantee you if it's complete and working it will run you more than $3500 in this same condition.
Vendo 81's that need restoration prices have remained flat for a while now, so have restored ones, however, nice originals have been going up because they are getting very tough to find. Hard to say exactly how nice this one is but from what I can see I like it a lot.
Now, were you planning on using it or just for show? I'm asking because if you wanted to just display it you can always deal with the compressor at a later time.
Long story short, I would grab it even at 3K.
These people just had the machine for show. He basically told me that if he would rather get the cooling system fixed himself and keep it than sell it for less than $3,000.
Not sure if everyone has this problem, but as I look for machines, it seems that everyone is putting a premium price on them. There is a Vendo 90 (early 60's) near me that looks to be in pretty good condition. The guy is asking $1,500. The little bit of reading that I've done here is telling me that he is about 3 times too high, and I doubt he is going to drop his price that much anytime soon. If I'm going to spend a bit to much, my gut is telling me to do it with a more collectible machine.
I'm thinking I'm gonna call the Vendo 81 owners and see if they'll still take $3,000 for it. Soon as I do that something better will come up
Thanks for the evaluation. You guys have been great help.