Dicks sporting goods has Wilson championship balls on sale for $16.78 for 8 pack. That about $2 bucks can. If you are in Ocala or Orlando might be worth it to stop. Sale ends 5th December. Cheapest tennis balls around is Walmart at $2.18 can when compared.
Also have golf balls on sale also, top flight XL or Maxfli two pack 18 or 12 for 20 bucks. Calaways and Srixon on sale also 2 for $35 bucks. For the serious golfer Titleist ProV1 or ProV1x for 39 bucks
FYI If interested?? OK, hold back the thanks