That's what its all about but....depth.
Having said that, a mate with a 2300 finds far more than I do. All little sub grammers near the surface. So small in fact, I cant even get a signal off most of the pieces he finds. They are more exe than the 4500.
By the OP's description, I think the 4500 is a bit out of his league.
How do you make a small fortune out of gold prospecting? Well you first start out with a large fortune, and by the time you buy equipment and pay for fuel, you end up with a small fortune!