Well not even $100 but pretty close once tax and shipping was added. But I just picked up DUI's weight & trim II harness weight system. I always told my self that I'd never pay that much for a fancy weight belt but that changed after only one use. I tried it on my last dive and didn't even realize I was wearing weight until I started to ascend. I wore the waist clip really loose and had the weights a lot lower than normal and I loved it. Also on land it felt like a lot less weight because it's not just on your hips.

So what was your last great purchase that was relatively inexpensive?