Assuming you keep the FW oiled, how quickly do cheap FWs die? Are they prone to failures or have teeth that wear out faster? What is the price difference?

I have mixed feelings about using cheaper parts and replacing them more often. Clipless pedals, where failures could result in injury and breakdowns that cannot feasibly bve done on the road are one place where I go cheap. Forte LOOK copies. $40-50. I replace them when I start having doubts. Pick them up when I see them on sale. (The Deltas are gone, so I may have to rethink this when my last is on a bike, but it has been a 15 year run and a lot of miles and I think 1 mishap. I have generally had two pairs on bikes at any given time.)

If the cheap ones go reliably say 7000 miles and cost 1/3 the WIs, I'd say "why not?".

Ben