30k

Insert image through URL. It allows you to bypass limit.

25k

well.. you go to the thread, whereas you uploaded your last images and delete them to make room for more, however to keep to them. You click the X on them to remove them but you don't save the changes to the post. That effectively keeps the images there in the thread but doesn't keep it stored in your attachments and gives you the room needed. Referenced Thread whereas the pic still displays although removed:   

New auction, starting price of 5k. Bids can increase by 5k. The auction ends 48 hours after the first bid. Payment is due upon acceptance.