Baseballs are durable and last a long time. If you don't mind cosmetic wear from use, buying used baseballs can save you lots of money. When buying used baseballs there are a few things you want to consider. First you want to make sure the stitches are intact and do not come out loose. The cover should not fall off, the ball should have a good, even weight and should not become waterlogged. Overall, the ball should maintain its shape and not become uneven or lumpy.