I haven't done a test ride on any of the C&V bikes I've bought, but then they were all under $500 and I could tell by looking at them and measuring whether or not they'd fit, and since the first thing I'd be doing to them was tearing them down and rebuilding them, how well they were working at that moment is pretty much moot. Hell, one of them had a tire - possibly the ORIGINAL tire from 1982 - where the bead had popped off the rim!
Often C&V bikes are just pulled out of a garage and the tires inflated a bit. Owners might or might not check the brakes and shifting, and in the case of all but one of the C&V bikes I've bought in the last couple years, I wouldn't trust the bike to go and stop properly before I'd worked on it, and this incident highlights why.
In this case, if you want the bike, and the price is affordable for you, I'd just pay it. As my wife says, "Tuition in the school of life."
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"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles