[kolinko]

There are also cases of people selling cars (and other stuff) ultra cheap on ebay, because they misplaced a comma when specifying a price.

It was obvious that the price was supposed to be $20k, not $20.000, and yet the seller lost.

[sandworm101]

Prices for the sale of consumer goods are subject to some special rules, mostly to prevent bait-and-switch advertising. But actual typos happen all the time and are corrected. There are a great many instances of airline websites getting prices horribly wrong. These contracts are not normally honoured and wouldn't be enforced by a court (40,000$ tickets for 50$ sort of things). Much depends on the specific facts and whether the price is obviously a mistake.