Looks like you missed the decimal point when you set up that auction.
When you cancel your bidder, politely thank him for his confidence in you and apologize for your 'fat fingers'.
His bid shows as 99 cents, but it may actually be much higher.
His true bid would only be revealed if you got multiple bidders.
The polite note is meant to encourage an honest bidder to come back and try again to win your lot.
Politely.-- Captain Malcolm Reynolds