Using different acrylic paints

Those guys are right on. I'll add that if you're looking for a cheap hobby, this ain't it!! Try to cheap out and you will just be spinning your wheels and frustrating yourself. If you're gonna put in the effort, don't you want it to stay that way?

Like patraw said the cheaper paints generally dry with a chalky texture that is easy to chip. If for any reason I do need to use these paints(sometimes there's a color I want that I can't find in another brand) it's very important to seal the paint afterwards with matter or gloss krylon spray sealant. This gets rid of that chalky texture and makes it more chip and wear resistant.

The cheaper acrylic paints in craft stores tend to dry chalky and are often villified by the customizing community. That said, I use the el-cheapo Apple Barrel and Folk Art brands (I get 'em from Wal-mart, but I imagine they can be purchased elsewhere as well) all the time (because I'm a miser), but, bear in mind that my figures are usually made out of paper, not plastic, so, while they work well for me, they might not necessarily do so for you.

Quality paints are an asset, but technique/skill are just as important, if not moreso.