I bought a supermoto strictly because I wanted to race motorcycles and it was a much cheaper alternative to the MRA.

No license.
$50 is the most you will spend on a single class (you get discounts for every class you race per weekend after the first class)
$45 season "membership"
Reputation as a friendly series.

Plus, the bike is cheaper, tires are cheaper, crashing is MUCH cheaper.

I'll stick with supermoto5280 for a while.