American Law is almost universally the opposite - HOWEVER it doesn't completely unlimit it - you'll see signs at grocery stores that say something like "in the event of a price error, the store must give you the item at the listed price refund the difference"

For example, Wisconsin:

98.08 Price refunds; price information. (1) A person who uses an electronic scanner to record the price of a commodity or thing and who sells the commodity or thing at a price higher than the posted or advertised price of that commodity or thing at least shall refund to a person who purchases the commodity or thing the difference between the posted or advertised price of the commodity or thing and the price charged at the time of sale.(2) A person who sells a commodity or thing and who uses an electronic scanner to record the price of that commodity or thing shall display, in a conspicuous manner, a sign stating the requirements of sub. (1).

https://glitchndealz.com/glitch-laws-by-state-pricing-error-...