It's largely dependent on your intended use. Generally acrylic aquariums can last a very very long time. I haven't checked prices in a while but 3k doesn't sound out of line. Acrylic is a lot sturdier than the glass counterpart but can also be scratched easier.

Are you trying to start a fresh or saltwater? Personally I recommend salt especially with an aquarium that size, but the expense is much greater. As far as pumps, filters, lights etc., it is largely dependent on Fresh or salt and what creatures your trying to keep.