Where to buy the X out/XXX tennis balls wholesale?

[MattyB]

Hi, Im a high school tennis player who is looking to practicing serving, but I want to buy a bunch of balls without breaking the bank, I know that the XXX balls that are defective and cheap but also good but haven't been able to find a seller who sells a case or wholesale.
Can someone tell me where I can buy XXX tennis balls to practice?

 

[Jer Yu]

Honestly I have never heard of XXX balls. But you can get regular Penn Extra duty balls at costco. I think they sell the whole case for $40 if I remember.