Get a fitness ball, they will be much cheaper then a bench and much more versatile.

For pretty much all the exercises you do on a bench you can do them on the ball, and it does much more for you then on a bench. Doing something like a dumbell press on the ball will take in much more muscles and provide a better training effect then doing it on a bench. You can also do literally hundreds of trunk (Stomach and Back) exercises on it.

In my opinion money much better spent!