A UK seller on eBay sold a bunch of these last year (i.e., 2-3 weeks ago) for $57. Now they're $71. Crap. http://www.ebay.com/itm/omega-sp-ma...811975?hash=item33b0384d87:g:CbQAAOSwcOFWasyLPurchases made through these links may earn this site a commission from the eBay Partner Network
Ofrei prices have gone up a lot too in the last six months - like >30% for some stuff - and those aren't even vintage..
Demand steady to rising + Supply falling off the cliff = Prices rising and rising and rising. I suspect many hard to obtain pieces will be priced more according to how much value they will add to the watch in question rather than the inherent value of the part plus typical markup.