1 MH/s cost USD 44 for one year
if you see this ether calculator
http://badmofo.github.io/ethereum-mining-calculator/
Month 0.991780 $5.14
you will generate this amount ..
so you need 9 month to get ROI ..so which is not worth to buy it right now as per the price rate ..
Once it lower you can decide ..
There is a good change Ethereum is gonna explode in price, than this calculation would be different right...