(*) I'm not sure if any (solo) pool will support low hash rate miners in the future. Pool operators have to pay for their hardware and connection, and a low hash rate miner costs them as much as a complete mining farm. Maybe CK can answer that.
I think 0.2th - 0.25th is and will be for a good period of time enough hashrate to reasonably connect to any mining pool, it's completely fine if I get a valid share every 5 mins instead of every 5 seconds, the pool manages its resources through share difficulty and the hashrate of the device is irrelevant to them, they maintain certain traffic between their server and your miner/proxy by raising/lowering the difficulty.
Now the real question is, what is the price tag? I know you said you don't know, for you to get answers you need to find the answer to that question first, i might be interested in buying a few if it was $50, maybe buy 1-2 if it was $100, ditch the idea altogether if it was $200, so ya, sadly, it all boils down to the price.