It’s Austin. Best to let them breach the contract and move it 50 miles away (outside downtown and suburbs of Austin). There is no way to win as they will simply change the rules and judges/juries are bought and sold there.
There are already gun shows in nearly every community that is 50 miles away from Austin.
Belton, San Antonio and others have their own gun shows. Austin is a pretty big gun market (in spite of the city council's preferences) and you wouldn't want to force your customers to drive 50 miles to do business with you.