building a computer within budget! help!

[freshmint224]

I'm currently considering revamping my entire desktop as it has been giving me a lot of problems. Now I want to replace everything but my DVD drive, cooler master 912 advance and monitor. Everything else replace. I'm hoping to include more fans into my CPU as my room is not quite ventilated. There's no need for overclocking. I just want to play games like Dota 2, csgo, payday 2, LoL in highest graphic settings. I'm also probably turn to more fps games after my army. So I need it to last so that I wouldn't have to upgrade anytime soon. Probably i5 motherboard. My budget is currently place around 800 sgd. Please help me! I have near 0 knowledge about computers

 

[Ahmadjon]

800$?

 

[AMD Radeon]

you can start from here and use this build as preference only, find similar items in Singapore local store

PCPartPicker part list / Price breakdown by merchant / Benchmarks

CPU: Intel Core i5-4440 3.1GHz Quad-Core Processor ($174.99 @ SuperBiiz)
Motherboard: ASRock H87M Pro4 Micro ATX LGA1150 Motherboard ($79.99 @ Micro Center)
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1866 Memory ($72.25 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($57.98 @ OutletPC)
Video Card: Sapphire Radeon R9 270X 2GB Video Card ($215.38 @ Newegg)
Power Supply: XFX 550W 80+ Bronze Certified ATX Power Supply ($44.99 @ NCIX US)
Total: $645.58
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2014-03-22 01:36 EDT-0400)

 

[freshmint224]

The prices listed is sgd?