What would a Ruger P-90 DC in stainless steel go for these days in excellent shape?
Completed auctions (with bids) for P90DCs on GunBroker are mostly in the $350 to $450 range, with some higher and some lower. Guessing a stainless version in excellent condition might run towards the high side, especially if it has extra mags, box, etc. Keep in mind that buyers on GunBroker also have to pay sales tax, shipping, and transfer fees.
There is a thread here on the forum about how Ruger single actions are going up in price, and the same thing is apparently happening with P-series pistols. Below is a link to an auction for a very nice stainless P91DC with box, papers, etc., that grabbed my attention, with 3 bidders over $550:
P91s are a lot less common than P90s, but I didn't notice anything particularly unique about the gun. With tax on $581, plus shipping and transfer fee, the buyer was probably paying over $650 total. Prices are definitely rising!