The C&V market is thin and there is considerable variation depending on where you sell items (eBay, size of the city, etc.). But the market for this item is thin even by C&V standards. I have a set of the racing versions of these and they are fine pedals.
You need to find a comparable, I'd price them around the price of campy pedals. The question is do you price them around campy NR or SR. But I'd get a sense of eBay prices on these and price it somewhere in that neighborhood. You'll have to put them on the 'Bay to get top dollar for them. I don't think high priced vintage stuff moves too much here.