Well, with 99 Cents your're probably right, that it's been a mistake. I once had my limit - but not for a stamp auction - on 5000,- Euros.
Day by day one bidder got higher and higher, until he reached my limit. One hour later I got an email from
eBay, that I'm very lucky to have the highest bid again - 4995,-
First I was really angry about that, but there was no need to. If you get the highest bid this way, you cannot be forced to take the item. Your bid expires immediately, when someone makes a higher offer. So a short "I'm not interested anymore"-message, and that's it.