you can check the mylittleponycollector.com for a price range. i think it might be around $25 to $50 a piece or higher. the only thing i'm sure of is that it's pretty rare.
I paid $40 BIN for the blue one rehaired by Kcat, $50 for the pink one, and $70 for the yellow one since I wanted to complete the set so badly LOL. The first two were last fall, the yellow one was just a couple of months ago, if that helps. :?:
Hmm. Rares can be a tough call, can't they? I looked it up on Lavonia's site, and it says $25-$90 depending on condition.
I BIN'ed all three in near-mint condition for roughly $40 a piece today, sort of on an impulse. Just wondering if that really was a good deal or not. *shrugs*