I'm going to buy them and exchange the BTC for Litecoins, which currently cost waaaay more power to generate in comparison. So I really don't feel bad. I will keep them running until they can no longer profit.
You would do better to buy some bitcoins and use those to exchange for litecoins.
Or, you know, buy some litecoins.
If you buy a block erupter at this price, you are guaranteed to get less bitcoin than if you just buy bitcoins. You will also get those less bitcoins over a longer period of time than just buying some bitcoins. So if you want bitcoins, buy some bitcoins, don't but a block erupter.
Same logic applies to litecoins.
The difficulty has to increase by two orders of magnitude for these to become totally worthless in terms of power usage versus mining income. I plan to run them for the next couple of years. I'm not really worried. If they lose money, so be it, at least they're not costing me anything to run and they are securing the Bitcoin network.
The per watt efficiency is similar to other manufacturers out there, so as long as they are mining profitably, probably I will be too.
In the meantime you're welcome to disseminate your money to operations who will ship in "September" or "October" or whenever, who will probably use your funds to buy ASICs, destroy the network difficulty with them before shipping them out, and then send a slightly profitable brick to your doorstop (as we're seeing with Avalon and BFL, and as I'm sure we'll see with the Klondike etc manufacturers).