The driver's door window regulator broke on my '01 Accord 4Dr with power windows.

The cable that pulls the window up pulled out of the plastic retainer. Then the cable got caught up in the pulley on the motor and both cables and the pulley got destroyed. It looks like none of these parts are available as individual parts, I can only buy the whole system (motor, regulator, cables, etc) so I'm looking at a $150 repair thanks to a 50 cent piece of plastic.

Before I shell out $150 I've got a couple of questions:
Is there some place where I can find these parts as one off's instead of buying the whole system? Honda eparts and hondapartsdeals.com only list the whole system.
Is this a common problem and is there some preventative maintenance I can do to keep this from happening again on one of the other 3 windows?

 

The parts counter guy at the Honda dealership was familiar with this failure so it must be fairly common. He says there hasn't been a TSB, but he's seen it before. I found some old posts here that would indicate this is a weak design.

The new parts aren't any better designed that the old ones so I'm going to try and fabricate a reenforcement out of some sheetmetal to spread the load out over the plastic better and keep the plastic from deforming.

 

Rather than going into fabrication (unless it's your thing to do)
Lubrication is a great key to preventing the breakdown of the regulator. Dry cables will cause more friction on the plastic and cause more rapid wear. Lubricated cables will not cause as much friction on the plastic and the wear will be greatly reduced.