Hey, the price was right for the sub, right? We all gotta start somewhere, but that would be on my short list of stuff to improve on.
Like HD said, the difference between 80 and 100 watts is pretty trivial when you're talking total volume.
Here's a cool little tool we all like to play with that can give you an idea of the relation between volume and power. Just fill in the info in the boxes and click "calculate"