Hey Adam. Wherever you got your detector, and for whatever price, it's performance is really dependent on your skills.
Every detector out there will find metal, and most (yes even the cheapest) use some variation of the same technology.
If you paid $80.00 for your unit, I would say that whatever you ended up with, you got a good deal. Prices I have seen on the web run in the $150.00 range.
The way I would approach this is to read the manual very carefully, and carry it into the field with you. Then start looking. You will for the first couple of weeks / months want to refer to the manual occasionally while hunting.
Then learn your machine. Don't get all wrapped up in a detector upgrade until you can find targets with your current unit.
You will have to put in 50 - 100 hours before you can "know" your detector. Then if you like the hobby, you might want to trade up. By trade up, I mean additional features like more precise discrimination, notch filters, target indicators, etc.
If you have another $150 laying around, I would spend it on a Garrett pinpointer before I upgraded the dectector. (you will never have to upgrade that pinpointer)