Probably legal, I do not see anything strange that could make such a thing illegal. Most of the answers here are also legal, meaning many think that selling bitcoins with cash is legal. I do not know for sure, but it seems legal.
indeed it really depends on the country we live in, which can indeed distinguish its legal status, if we leave a country that supports bitcoin, then the status is clear, legal, which is a problem if we leave the country rejecting, the status changes, illegal, so Bitcoin status depends on each country.