Seems weird that you have such trouble with GPU's. Not that I'm an expert in such things. Maybe they're just allergic to your rig.
When I buy a new GPU I toss the old ones towards hubby, if he wants it, since he doesn't care at all about graphic bells and whistles. So typically they're still going/seeing use 3-4 years later. There's only been one card I bought in all these years that failed within a year.
I could understand it if it had been the same rig, but just about everything was replaced at the same time. First few cards died on the old PC and the recent batch of cards on my current PC (the last card did last almost 2 years though).
I have an old Leadtek FX5900 card which is still chugging away in my old Pentium 4 archeotech computer (it's AGP though, not PCI, so I can't use it elsewhere), getting close to its 10th year