plastic are notmaly just fine. you get a little distortion, and it can scrach but if that dosent bug you then it is fine. also some pet store have really good sales look in the phone book and find out if they are having a sale.

If you live near a Walmart, they have great prices on aquariums of all shape, sizes and colors.

I'd suggest looking in your classifieds for a glass aquarium. They sell things for cheap and usually in great condition.