I listed an 8lb jug of H4350 (not here) for $300 and got flamed for price gouging even though I pointed out the same item had multiple listings on GB that had bid up to $500. To be fair, I only listed a cash price because site rules required it and clearly stated that my preference was an even trade for a different powder equally scarce.
In the meantime, while the flame war continued (only a little bit of the gasoline was my own unashamed defense), GB bids went to $600, one got snapped up for an $800 BIN and new listings increased their BIN to $900.
A few days later after I found what I needed and withdrew my offer, several online retailers received Hodgdon shipments and how would you feel if you had a $600 bid, the auction was still open and you could buy it online for $220 + S&H?
Online stocks got wiped out in minutes, not hours. The current market value actually changed from $600+, to ~$240, then right back to $600 within hours. Market value = willing buyer + willing seller. Always.
May you live in interesting times.