Cheap or expensive -- Which bottom bracket to choose?

If you've read my previous post on the toll of winter, you know that my bottom bracket is grindy. I haven't kept exact records of how many kilometers I have ridden with it, but I'm pretty sure that it's only about two years old and definitely has less than 10 000 km on it. That's pretty disappointing for a cartridge bottom bracket. I've looked at different options for a replacement and it was hard to decide between them:

• get another cheap Shimano cartridge BB and hope that this time it will last longer?
• get the really nice SKF bottom bracket that has a 100 000 km/10 year warranty?
• move away from square taper BBs and try a external bottom bracket system?

The last option I did not really consider. My cranks are still in good shape, as are all three chainrings. In addition, people's experiences with external bottom bracket systems appear to be mixed. In theory they seem like a great idea (easier to install, larger bearings) but in practice it hasn't quite worked out like that. Therefore, it came down to deciding between cheap and expensive. Interestingly, in the world of square taper bottom brackets there isn't really any middle ground: square taper system have become less and less common and SKF is, as far as I know, the only high-level option.

I was really tempted by the SKF bottom brackets, currently only distributed by Compass Bicycles. A 100 000 km warranty (given my annual mileage it would probably be the 10 years that come first) is pretty impressive, and as exchanging bottom brackets is one of the more time consuming maintenance items it can make a lot of sense -- install and forget! The price for those carefree 100 megameters is fairly steep, though: 129 USD plus shipping (and probably taxes and customs for us Canadians). Compare that with the cheap Shimano option: at the LBS, a UN-55 bottom bracket costs 30 dollars, meaning I can buy four to five Shimano BBs for the price of one SKF (if you live in the US you can get them for less than $17 shipped on Amazon. Simplistic rational choice economics would probably tell us to go for SKF: if my new Shimano BBs are going fail like the last one, at only 10 000 km, five of them will only last for 50 000 km -- versus the at least 100 000 km of the SKF. But what if the SKF breaks down before that and I'll have to pay for the shipping back to the US? And are kilometers the right metric if I'm riding less then 10 000 km per year anyway? What if my bike gets stolen (not that unlikely in Montreal)? What if the new Shimano bottom bracket will last much longer than the previous one, as they do for a lot of people? On the other had, isn't buying cheap but crappy things horribly unsustainable and making me a bad person?

Those are all legitimate questions and to some of them there are no easy answers. In the end, I bought another Shimano BB UN-55: The LBS had them in stock, a 30 dollar hole hurts much less in my wallet than a 150 dollar hole, and I'll just have to hope that this time I'm more lucky.

Which trade-offs do you make in the realm of bottom brackets? Have you moved beyond square taper and Octalink? Or are you a retrogrouch with good old cup-and-cone bearings?