If I post an item for auction and with a buy it now price, can it be bid higher than the buy it now

[cillab171]

perhaps the buy it now is set too low, can I fix that after it has been bid on?

[wooden_flower]

In almost all categories, the buy it now price goes away as soon as there is a bid.

Bidding can go as high as your buyers are willing to pay - the buy it now price is not a ceiling.

[woodland_gnome]

The BIN option goes away (general rule:  it goes away with the first bid; exceptions: it remains up if there is an unmet Reserve Price or in 4 "Sticky BIN" categories if the "current bid" on the auction is less than 50% of the BIN price) at some point in the bidding BECAUSE eBay doesn't want it to act as a price cap.  The final auction price is the highest bid of the second highest bidder plus up to 1 bid increment (or the exact Reserve Price if only 1 bidder bid that high or near it).