After doing research online, here are some of the best bang for buck mice around:
Priced at 39 dollars, it is targeted at players who go for real time strategy games as well as massively multiplayer online role playing games. It supposedly allows for 1200 actions per minute (APM) but of course few players will ever intend to reach that. The krait is currently Razer's device that is targeted towards the budget gaming mice market. It has the usual 1600 dpi and non slip buttons, and like many other gaming mice will not switch off its engine. Its pretty much a smaller diamondback which was pretty good in its time. If you want a mouse from the famous razer than this is a good preview. Its build quality might not be that great though, so be wary that you may have to send it back to the shop if its under warranty, which is actually rather good and long.
Mx 518 (Logitech MX 518 Series)
For the best bang for buck, one could do worse than the Logitech Mx 518 gaming mouse. It is still used by many professional gamers today and has received widely positive reviews, being the best mouse in its price range. On the whole it wins on decent build quality, good ergonomics, an engine that keeps up to the higher resolutions of today (1800 dpi). It looks quite okay for a 35 dollar mouse and handles well. People have used it for years without facing any problems and you will find few people who have many complains with this mouse.
The cheapest mouse that is still in use now would be the Logitech mini optical mouse. Keep in mind that it is only good for mouse that are in the resolution ranges required of the best starcraft 2 gaming mouse though. That would be about 800 x 600 resolution. These optical mouse sell just under 20 dollars, and can be easily less if bought online. This mouse is still highly used by the korea pro gamers for the tournaments relating to starcraft, some of which earn 6 digit salaries and prize awards a year.