On the other hand the btc price in USA is relatively high compared to other countries. Guess this is due to more stringent AML monitoring in US. As a result people are willing to pay more to use BTC.
That seems counter rational to me. Usually, you get better sell prices because of the increased risk of the method of payment -- more chargeback risk and less stringent AML/KYC procedures like Paypal, for example. At least in my case, at places I use to sell where I have to comply with AML/KYC, the tradeoff is slightly better prices and more convenience.