I pretty much agree with what you're saying, but am still of the opinion that any mixte in clean ridable shape is worth $120. Weight and such really depends on the intended use - you're not likely to notice an extra 5lbs cruising across campus, but it might be a big deal if you're crawling up Griffith Park.

I've pulled apart and rebuilt a ton of old Signets, DLX's, Accordo's, and Cavaletto's. While built with varying degrees of inexpensive steel parts on what we would consider low-end frames, I've seen enough to know they are sturdy and reliable, and make perfect campus/path/city bikes.

The Le Mans is a good recommendation, but a quick CL search of the greater LA area yields two Le Mans possibilities(58cm), at $175 and $200 respectively, about 40-40 miles and endless traffic apart from each other. Ebay didn't turn up Le Man's specifically, a few Centurions in general, and only one Centurion on the small side - a Sport DLX that, if it goes for the minimum bid, will still cost $100 by the time it gets to the door.

For unremarkable (read common, every day) bikes, eBay would be the last resort for me, for a couple of reasons - 1)shipping charges are about as much as the bike is worth, and 2) I can't see what I'm getting for my money before it arrives.

I still say a clean bird in the hand is worth two dirty birds in the bush.