My left pedal went the other day, probably b/c I am a little over the recommended 200lb limit
It's not complete 'gone', but it turns at an angle when you pedal, as something is off the axis.I bought a new set, which didn't fit... (wrong stem diameter)
I then put on a set that I took from another bike, only to realize today that the pedals I am replacing are foldable, and the ones I've put on are regular.
Where to get a durable replacement that won't cost an arm and a leg?
Well those are cheap, but I would not expect they would be any more durable than the ones Downtube sells stock. Maybe try some alloy pedals this time? MKS is a good brand. Those $27 pedals are part-alloy. For full alloy folding pedals you'll spend more.
I prefer MKS EZY quick detachable pedals to the folding pedals (they allow me to attach PowerGrips), here is an example of those, but they do cost a lot.