Originally Posted by
Leviticus
CPU
$69.88
AMD FX-4300 3.8GHz Quad-Core
MOTHERBOARD
$59.99
ASRock 970M PRO3 Micro ATX AM3+/AM3
MEMORY
$49.99
Corsair Vengeance Pro 8GB (2 x 4GB) DDR3-1600
STORAGE
$45.88
Seagate Barracuda 500GB 3.5" 7200RPM
VIDEO CARD
$104.99
MSI GeForce GTX 750 Ti 2GB TWIN FROZR
POWER SUPPLY
$35.49
EVGA 500W 80+ Certified ATX
Total: 316 + Case Cost + Fans would run you around 400-450~
And you can find you a case around 50$ if you search.
This will be good enough to run League and Runescape with no problems, I would also suggest to get a fan or two. Preferably water cooling but fans will do just fine for the type of gaming you do. Also to save some money on fans, Just get a case with fans.
Also if you ever start upgrading, I would go for the CPU First to around FX 8350 or better.