There are plenty of affordable gaming mice on the market, but the best gaming mouse for buyers on a budget is Logitech's G203 Lightsync, a model we reviewed several months ago that left us impressed. It is a good buy at $40, and an even easier recommendation at its currently discounted $14.99 price tag
It's marked down to that price at Best Buy. It's dipped down to that same price a couple of times since late October, and is again at its all-time low right now.
Don't be put off by the dirt cheap price tag. It's a budget rodent, yes, but normally in this price range you're left sifting through generic mice with not a whole lot to offer. In this case, you're getting a "gaming grade" 200-8,000 DPI optical sensor, six programmable buttons, and three-zone RGB lighting (which is the main difference between this and the Prodigy, which has single-zone lighting).
On the ergonomics side, the mouse sports a near-ambidextrous design, meaning the shape is not angled in either direction, but the non-removable thumb buttons permanently reside on the left side. So, this is another gaming mouse for right-handed users.
If nothing else, at this price it is worth picking one up and tossing it on your parts bin to use in a pinch.