I think your best bet is to find a cheap S3 around $80 and start mining with that. It's a lot more profitable than a usb stick miner.
If you are set on a stick miner than sidehack has a really good device coming out you can grab and mess around with
Honestly USB stick miners are a different category to me. They are more for learning and lotto.
With ROI a bigger machine normally is better as far as price per GH.