See this wiki page.
Basically, lowest listing goes to the highest bidder. Someone listed the item for less than you did. When someone bid the 500,000, it went to that person who listed lower than you.
Global @StarGeek
ParagonWiki.com-The original is still the best!
My Hero Merit rolls
Accuracy needed for 95% ToHit spreadsheet
Forum font change stripper for Firefox/Opera/Chrome. No more dealing with poor color choices, weird fonts or microscopic text
Search Wiki Patch notes, add site:ParagonWiki.com inurl:patch_notes to your Google Search
Oh, OK thanks.
Last week I put a recipe up for sale for 250,000, and it's still not sold. But a couple days ago, someone else sold that recipe for 500,000. How could the higher price take precedence? Do older sales take priority over newer ones, without respect to price (except of course that it doesn't exceed what a buy offers to pay)?