That $17 PSU will be very expensive, because when it dies it will fry your motherboard and your GPU with it.
The LAST part you should go cheap on is your power supply. The PSU is the heart of your computer and your components needs reliable stable power, if your cheapo PSU sends 6.5 volts down the 5v connection your parts are toast. The cheap PSUs are made with the cheapest parts they can find, this means poor accuracy and poor reliability, it also means that they skimped on protections (like short circuit protection, over voltage protection, etc) which is what prevents your PSU from damaging other parts.
There have been numerous cases where these cheapo psu's have sparked and caused fires, burning peoples homes to ashes.
So with all of this information do you still think that you "save" $25 by getting a cheap PSU?
Outside of a 1 in a 1000 deal on craigslist you are not going to find a anything worth a crap for $20 or less.
A quality PSU is part of the cost of gaming,and you should not even try to game without one.