because I don’t think anyone can argue that a patch on an already compromised radiator is truly as good as a new factory radiator, and some of us are willing to pay the $280 for that peace of mind.
1. I think you're underestimating the strength of a properly done JB Weld. You can patch an engine block with that stuff and it'll hold for tens of thousands of miles if done properly. Add fiberglass reinforcement and it should be even more reliable!
2. I'm seeing repair costs in this thread quoted at WAY higher than $280. Maybe $280 if you do all the work yourself, but either way, it's a huge cost in time/money/labor vs. a simple, cheap, quick and effective epoxy patch.