If you've got a bunch of old golf balls that you don't want, consider selling them to a purveyor of used golf balls. You'll get paid in cash or credit to spend on golf balls that you do want.
Many of the used-ball retailers will buy your cast-offs only if you have a minimum number, which can be in the hundreds or thousands. But Golf Ball Nut makes it easier, requiring only 120 balls.
For each 120 accepted balls, you'll get a $20 credit to spend on their website. Golf Ball Nut only sells used and refinished balls, but if you get their Mint grade, they'll be nearly indistinguishable from new.
What are acceptable balls? No range balls or cut balls. And they must be at least 75% pro line balls (Titleist, TaylorMade, Callaway, or Bridgestone).
To get the balls to Golf Ball Nut, they'll give you a FedEx label. Box them up and ship them.
Do you have the balls?
If you're like me, you may have buckets or boxes of old balls stored in your garage. If not and you live near a golf course, spend a little time ball hunting. Or when you play, purposefully look for stray balls, keeping the best ones worth playing and selling the rest to Golf Ball Nut or another retailer, listed below.
Don't send in poor-quality or beat-up balls, though. Golf Ball Nut "reserves the right to reassess the trade-in value of golf balls received following inspection based on product condition, quantity, and models." Avoid sending in cut and out-of-round golf balls, antique balata balls, and golf balls that have been discolored by the sun or sitting in water for a long time.
Other ball buyers
As mentioned above, other used-ball retailers also accept balls from the public. Here's a list, with minimum amounts required for acceptance.
We Buy Golf Balls - 300 or more. Pays cash.
ReUse Golf Balls - 2,000 or more. Pays cash.
Golf Ball Buyer - 5,000 or more preferred; may accept smaller amount.
Lost Golf Balls - 5,000 or more. Pays cash or store credit.
Golf Ball Planet - 10,000 or more. Pays cash or store credit.
California Golf Balls - 15,000 or more. Pays cash.
Found Golf Balls - 15,000 or more. Pays cash.
Golf Ball Monkey - 18,000 or more. (Smaller amounts OK only for Texas residents.) Pays cash.