I can't change the auction once it's been posted. Maybe I'll do another auction soon where it's a tiered auction...the more points bid the more you get.
If no one else is bidding then it doesn't matter how high you bid. It won't go over 10 credits if you're bidding alone. Even if you put a million credits it will only give me 10. So my suggestion if you want more stickers would be to bid on my other posted auctions.