The Broxa is a bargain basement gun. It's about the lowest quality gun you can find that would be remotely competitive against higher quality airsoft guns. It has decent accuracy and fire rate, and a good muzzle velocity (too good really for the newbies that tend to buy them). The issue is life span and quality control. It'll serve you fairly well for as long as it lasts, but that time frame may be pretty short. It's even possible it'll be a lemon right out of the box, though in that case you can probably return it for at least an exchange, depending where you bought it.
Get the highest quality gun you can afford, you'll thank yourself in the long run. Upgrading a low grade gun to match a high grade gun almost always costs considerably more then simply buying the high grade gun in the first place. Not to mention having your gun break down on you in mid game due to cheap parts sucks rocks.
Another thing to consider is resale value. You don't want to spend too much cause you're not sure you'll stick with it? That's actually a good reason *to* get a high grade gun rather then not to. You spend $600 on a Classic Army gun and, provided you've taken decent care of it, you have a very good chance of recouping most if not all of that $600 back. On the other hand, the classifieds are continuously flooded with people trying to offload Aftermath guns with no luck.