Oh, agreed. I've seen multiple rounds of friends deciding to save money on a cheap PC, trying to do real work on it, and finding the result a crashy erratic data-corrupting horror that is almost impossible to debug unless you have a second identical machine to swap parts out of... and losing years of working time to these unreliable nightmares. I pay a bit more (well, OK, quite a lot more) and those problems simply don't happen. I don't think this is ECCRAM, though: I think it's simply a matter of tested components with a decent safety margin rather than bargain-basement junk.
EDAC support for my Nehalem systems landed in mainline a couple of years ago but I'll admit to never having looked into how to get it to tell me what errors may have been corrected, so I have no idea how frequent they might be.
(And if it didn't mean dealing with Dell I might consider one of those machines myself...)