1. consider shipping costs-negative or get from a group-better
2. it does NOT mine-it gives you a chance in a lottery, which with your miner being ~1/100000000 of the network, would work out for 1 block in ~200 years at the current difficulty. However, it also means that for every 2000 sold and being deployed 24/7, one will score a block within a ~year on average (with current difficulty), but the other 1999 will produce NOTHING. I did a rough estimate-numbers could be off, but it is what i got.