a while back, the market was flooded with cheap wheels with disc dynohubs. The supply seems to have dried up, but you probably can find something. Shimano makes a cheap disc dynohub that goes for the same as the Sanyos and Sram hubs. Actually, you might find a deal on the Sram hub, it works fine

There is a company selling wheels from Germany on ebay. You could also check the german online sellers for built wheels.