If you owned your FirstLast.com, would you be interested in buying your FirstLast.xyz? I wouldn't.
If you had a generic first / last name and your FirstLast.com was taken, would you be interested in your FirstLast.xyz as an alternative? My name isn't generic so I can't answer. I would like my LastName.com, but it's taken. I have no interest in buying my LastName.xyz.
Why not reg your own name? If you don't, Adam Dicker, not the domain guru, might register your FirstLast.com and try and trade it for AdamDicker.xyz. I say this from experience. I didn't register the FirstLast used in my domain registrations, and, somebody registered my FirstLast.com hoping to get a deal for a recent expired reg of mine, a dictionary word, that happened to be their last name.