Now the ad is a total, complete, turn off! Anyone who tells me to check ebay for current pricing, I tell them go ahead and sell on ebay, where you pay all kinds of fees, you have to pack and ship, buyers win any and all disputes.
If I was super interested, I'd find the lowest completed auction for one that sold on ebay, subtract 20% for fees, and offer him that. Something like: " I took your advice, THANKS! Checked ebay, and this one sold for $795. It had all the original parts, and seller had to pay about $150 in fees to sell it, so I can give you $650." In person of course, and be nice about it. Even if seller is a jerk, its a one time transaction, so bear with it. Check for rust and stuck post or stem!!
Be sure to steer him away from ASKING prices. People can and DO ask crazy prices for stuff on ebay. Its what stuff SELLS for that matters. My standard line for people that focus on asking prices on ebay, "If I asked $20 on ebay for a $10 bill, would that make my $10 bill worth $20? If so, I'm heading to the bank!"
This one sold for $650.
https://www.ebay.com/itm/1974-Schwinn-Paramount-P15-9-Campagnolo-Record-/222973453554?hash=item33ea40e4f2%3Ag%3AIxIAAOSw-H1a9E1O&nma=true&si=5GlaDRIVGaWYQ2yB7f%252B32mZaMZ0%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557
This one for $600 sounds like it has been fully serviced:
https://www.ebay.com/itm/1977-Schwinn-Paramount-P-10-w-Full-Campagnolo-Nuovo-Record-23-034-Frame-L-039-Eroica-/382414580364?hash=item5909af6a8c%3Ag%3AUCQAAOSwW5larv27&nma=true&si=5GlaDRIVGaWYQ2yB7f%252B32mZaMZ0% 253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557