Well, that's a function of the 'true price' being measured in a different currency than the one you're paying in. Some retail businesses that accept foreign cur

Well, that's a function of the 'true price' being measured in a different currency than the one you're paying in. Some retail businesses that accept foreign currency rectify this with a flat exchange rate. For example, in Canada businesses (at least on Southern Ontario) will generally accept payment in USD instead of CAD, but they tend to have a flat exchange rate (e.g. 1 USD = 1 CAD or 1 USD = 1.10 CAD). If they priced the exchange rate to the current exchange rate as measured by some currency exchange, that would be different. You run into this same issue when using a US credit card in Canada. The credit card company will exchange (and usually charge an extra ~1% charge). IIRC, they use up-to-date exchange rate info, so technically the price in USD is constantly changing.