Cheap Carbon Fiber Wheels Right, I guess inserting where they're made in the title would be a little politically incorrect but essentially the link below would give you the exact product that inspired the question :-
Cheap Carbon Rims

The target is to use those for a cyclocross-commuter steel bike that I am building. The typical use of such a rig would be for home-work-home commute on cycle tracks with a muddy stretch of offroad along the way (short cut smirk). 

I am about 180 pounds (give or take) and have had history of taco-ing alloy rims before (MTB) - so the question would be : would you trust such a product for the above use?
Short answer: No.

Long Answer: I would not use carbon rims for commuting for several reasons:


They make the bike look more shiny than you want, attracting all kinds of unwanted attention.
I ride my commuter bike in any weather without too much maintenance. Should the carbon rim fail at some point, I at least won't notice a hairline crack until the wheel breaks. Carbon wheels will mostly break catastrophically, and that's not what I'd want while wedged between an SUV and a 40-ton lorry.
If you're using rim brakes (which the OP doesn't), pure carbon rims do not have the same braking performance as alloy ones, especially when wet.
With a seller on eBay, you probably don't have anyone to go to if the wheel is faulty from the start, e.g. arrives broken/bent or some such. Basically, you don't get any warranty.


So, I'd rather spend a more for custom-built wheels with alloy rims if you want maximum stability.