Mobo : M5a97 - Around 7.5k
PSU - Corsair VS550 - 3250
GPUs - 2x R9 270(Not X) - 29k ( will give around 900khash when properly configured)
RAM - 4gigs Value/Vengeance - 2800/3k
CPU - Sempron 145 - 1800
And you still have around 6k left for a case and HDD of your choice.
And yes that 550watt PSU will easily power the two 270s as they only require a single 6 pin and consume a maximum of 150 watts each.
So Max power consumption on the 12 volt rail is about 300 + 45(cpu) + 30(fan,HD) = Below 400watt and that PSU will easily power all that stuff.
If you invest more you could get an even better rig which will give you ROI faster.