Hmmm. Your budget is tight but maybe doable if you do rebuys with only really large denoms and then have players make change at the table but $350 won’t go far if rebuy stacks are same as staring stack.
Most T25 starting stacks have something like 12/12/5/6/x so ~40 chips. 20 x 40 already puts you at 43¢/chip before you even buy upper denoms and that’s just one rebuy each.
Maybe PM
@Josh Kifer to see what Isle Pompano chips he has left. Those were prices quite generously