I grabbed a USB asic Dash miner off ebay a little while back for around $80 and have been using it everyday. This device is really just for people that mine as a hobby and will probably only get you one or two dash per year at the current difficulty. The power usage is really amazing at only about 9 watts and is powered from the usb port. The speed is about 7.5 to 8 MH/s and with a low power Rasberry PI or a low power pc you wont pull more than 50 watts at the wall.
You can mine other x11 coins with this, but keep in mine it is limited to only x11 coins unlike some other asic miners that allow you to mine other X coins. This device beats a GPU hands down and requires a fraction of the power needed by a gpu to mine dash.
I paired the miner with a tiny liva pc as the miner controller and plan to run a modified scrypt (litecoin) miner on this controller as well.
Here is a screen shot of the miner in action on the liva pc.
If you like to mine for a hobby and find one of these on ebay cheap, it might be nice to add to your collection.