I'm surprised they are that expensive unless folks are raising the prices as BTC value rises. I bought three for ~$25 each in Sep or Oct. Might want to keep searching.
Even at $25, breaking even seems hard at this point unless you park them on an alt coin that will rise relative to BTC someday, which is how I made back the cost and then some. My erupters just solo mine now hoping for a lottery win....
Im brand new this week looking into bitcoins and other alt coins. I have noticed that 2 months ago block erupters were going for 10-20$ USD but now that the price of bitcoins has gone up atleast 5 times the price of the erupters has gone up the same, but at the same time the difficulty has gone up the same.
From what I take out of this is unless you are farming at 100 Ghash/s with equipment you bought at bottom dollar you are not going to gain much. I think this week ive made .0002 BTC with one erupter and my GPU will probably spending 5$ in electricity.