If you are riding trails and on the road from time to time, I think a hard tail is the proper bike. But you say you are looking to do dirt jumping as well, that makes it a bit more difficult to put you on a single bike that will do all well. I would still think a hard tail would fit the bill better than a full suspension bike, especially given your price point. If you were to find something at that price in full suspension, either you got a tremendously good deal or you bought a piece of crap.
I am a bit of a specialized homer, so I'd say look at a hardrock. Good solid bike, and it should last. It will also meet your price point. But, if you can spend a little bit more, the rockhopper will probably last you longer and typically comes with a little bit better components. But its base price is the upper limit of your budget.
Go to a bike store and test ride a couple of bikes. A good bike that fits you well is well worth the money.