How would you know you've never had a one-bit memory error correctable by ECC? There's no way to know ...
It's not that much more expensive. We're talking about $425 to put 2 GB of ECC Registered DDR (Kingston). Good grief! 2 GB! Add a $200 second platter and you've got great little OpenACS server for $1000.
Now think about prices three years ago for a decent SCSI-based server box with 1 GB, say a P733, and a couple of 9 GB platters ...
Consumers. We'll be bitching when they pay *us* to take their server boxes off their hands!