Do they pay local bands to play? and about how much could a local musician expect to get?

Depends on ticket sales

The more tickets you sell the better you get paid they base your pay on ticket sales alone but if you are a popular band that they know you might be able to work something out,they're good people

It's based on presale tickets. So it all depends on how many tickets you sell. The higher you sell the higher percentage you'll get back per ticket.