there's a difference between a private listing and and a supermarket doing business IMO, shouldn't be held to the same standard. Haven't you've been in this situation - you put an item for sale, only to realise the BIN set too low? it's only fair to change your mind and increase it.
No, I've never been in that situation. If I fucked up I just honor the trade.
Also, your example doesn't work for the simple reason if the "bin is too low" then what was the point of the reserve and "ft" prices. (don't use BIN when discussing euros, they rarely use that term). I never said they're obligated to sell the item. They're not in trouble if they don't. But pretending to have two different prices, one where it's marked down (when it really isn't) is just deceiving potential buyers. Again, not against the rules, again not every euro does this; but I've seen plenty of examples that do.
The bid/BIN system works 1000x better than the bid/res/ft system.