Putting a price on blueprint is not only difficult, is extermely difficult. I'v tryed to estimate my blueprints myself using peauction.com but it very hard. Sometimes people will give 10 peds for a blueprint, othertimes, people are ready to pay 33 peds for it. I bought one to day for 29 peds (QR ~ 33), other pay'ed 10 peds for a bp with same QR, and yet other again have payed 33 peds for a silimar one.