I think that for the time being this is not entirely profitable due to the sharp fluctuations of the crypto market.
But this idea is very interesting! Very soon we will be able to pay crypto currency in a variety of online stores.
Sorry, if this is a stupid question. I don't know what much about crypto. Couldn't you just always pay the Bitcoin equivalent of a dollar amount? What would be the downside of doing that? You would always have to convert, but that could be done automatically in an app, for example.