If you throw a lot and need lots of bats but you aren't laden with cash, here is something that may help. This is mostly for those with a table saw and a drill press (or who know someone who has the tools). There is an auction site called GovDeals.com. There is probably a good chance that schools in your area will auction off tables (a source of quality melamine). The tables can be cut down into ~8.5" x 8.5" squares, then you build a jig to drill the holes. The tip of course isn't the bats, it's the source for cheap melamine!