Vintage prices have only ever gone in one direction, and yes they are currently absolutely insane. What was extortionately expensive 18 months ago probably seems like a bargain today. However, something is only ever worth what someone else is prepared to pay for it. If you want to judge whether something is 'worth' the price / 'accurately priced' on eBay, I suggest checking the Sold listings to see what examples in the condition you wish to own actually changed hands for. Unsold listings with 'Buy It Now' prices are a poor guide, as they are likely to often be listed at higher prices than true auction listings finally sold for.
Patience and dedication are the best weapons in your locker for buying at the lowest prices you can find. If you've researched your prices via the 'Sold' listings (or elsewhere, like FaceBotch), I recommend regularly checking the new listings to wait for items that you want to appear at either reasonable 'Buy It Now' prices (hint: these will of course usually sell quickly), or else true auctions that you can take your chances on. I wouldn't be tempted to pay more than something's actually worth though, unless you do so with your eyes completely open, as the last 17 are NOT rare. They're expensive, but they are not rare, and if you miss one Yak Face to a higher bidder, there will always be another one listed very soon.
Hope that helps.
Jeremy
