Reliability is only a matter of board builder (EVGA, MSI, Sapphire, ASUS, etc...) AMD and Nvidia only build the chip on the board.
I found another card a little better : A R7 260 which perform 40% better than A Nvidia 650
PCPartPicker part list /
Price breakdown by merchant
Video Card: MSI Radeon R7 260 1GB Video Card (£67.97 @ Amazon UK)
Total: £67.97
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-01-06 21:03 GMT+0000
As you can see though, the R7 250X isn't on this chart, but you can say it is between a R7 250 and a R7 260