Hi , i am new here.
My computer spec as below:

mobo : gigabyte ga-ep35-ds3l
graphic : asus hd3650
ram : 2x 1gb ddr2
processor : intel E7200
HDD : 160gb

im not a very hardcore gamer and never OC it.
But i do play game from few hours to half day.
And i always have my pc on from morning till i sleep.
Recently issues like random power off happen.
I believe is my cheap PSu getting to its limit.
So any suggestion of worthy psu which does it job in my case ?
I have tight budget.... 
If possible give me a range of suggestion according to price range 
Thx !