Here is a small survey on the production of a Nano Sumo kit. If this idea is to be feasible, we will need your input. http://www.surveymonkey.com/s/HB72FTW
(by kit i mean everything needed to make one)
Seems like the price you might pay for this is not what it costs. While it is a small robot, that does not make it cheaper, actually makes it more expensive. I would say this would be impossible to make and sell at a reasonable price.