USAT pro license is a must and about $35 for the year. WTC pro license is totally optional and about $800ish per year.

WTC license only necessary if you want to do their particular events of course. Someone could certainly just do Lifetime/Challenge/Rev without a WTC license. WTC is the only race org that really charges pros to race, and the only one that requires pros to hold a "license" for their races.

Not complaining just stating