No, they won't, if everybody sells at 500g they will always be worth 500g even if only 1 person sells at that, to keep competitive others will sell at 500g and the chain is continued, for them to sell at 5K you would need everyone to sell at 5K or more..
not true, all it takes is for a few people to start selling at 600 and the 500 sellers will up theirs to match. Especially as they start to run low, people with only 5 - 10 left aren't going to want to part with them easily.