Teresa,
I haven't legally changed my name.for some issues ut basically procastination.
The process of change name and gender in the states is different in each state. As Jeri mention, for her was $3000 in Texas, for me, in California, it would be just $400 (rounding numbers) that can be waived if you proof low income, so it would be free. The process is easy and fast, no more than 6 weeks that the law needs you wait for someone presenting an appeal or seize to your change of name for any legal. After that they would give you a court letter to present on any federal office to proceed on legal documents.
When I go to a public place where have to wait to be called, I always ask to be call by Devi or just my last name, that had never failed.