Question: do YOU like your helmet and boots? If the answer is yes, who gives a crap what your friends like or have heard of, really.
If you like the way the helmet looks and fits, keep it. I’d only replace it if it is damaged or has suffered a significant crash. In fact, a $120 helmet that fits well is safer than a $300 helmet that isn't quite right.
O'Neal makes/markets good quality equipment for riders on a budget (you did say you are 15, right?). I'm quite sure that O'Neal helmets and boots are simply re-badged from other manufacturers. It just seems silly to spend $400 to $500 to make your friends happy.
But I'm a dad, so what do I know :)