What everyone said. Get samples, save the money, etc. However, between NexGens and PureClay I have to go with the Pureclay just because they don't have a metal slug, have a much nicer mold, and of course, great labels. Imo though they are very slippery, although after a few games they will be less so. Soundwise, though, they are not that great, they sound more like plastic chips than clay.
If you want to stay in your price range with less slippery chips you may also check out the neophyte chips from sidepot.com. They are a bit boring to look at, and have the same edge spot for all denoms but overall they are pretty nice. They cost about the same as the Pure clay and have a louder sound than them and shuffle ok. The labels can scratch a bit tough and you can leave a mark on the chip with a fingernail.
http://www.buypokerchips.com/neophyt...chips-s/28.htm
You could also try the new Sopranos. They are similar to the neophytes but only cost 7.5 cents and have several new colors. Not sure if you can label them tough.
http://www.discountcasinogear.com/st...ory62-120.html