This is not any "sudden interest". It has been 
happening for a while. If you check out that 
highest bidder's past auctions, you will find 
that she won quite a handful of auctions in the 
80,000 yen to 100,000 yen range, a few were even 
over 200,000 yen. Luckily, these awfully rich 
bidders seem to bid mainly on Heero, and 
sometimes Duo and Relena too. So cels of the 
other GW characters are not horrible high.