If you are set on a stick miner than sidehack has a really good device coming out you can grab and mess around with
The s-3 is stand alone just needs an Ethernet jack and a decent power supply.
In order to make profit 8 cents a kilowatt is good
I would agree it really depends on price of electricity. We can't say S3+ overall... as for some it will lose them money. I hate suggesting to someone a device that has no chance at ROI. Even a small chance is better then no chance.
And I agree on decent PSU. Some new to mining use horrible PSU's the worst thing I saw in past week is like 3 year old PSU and using molex to pcie adapter.
Get a PSU that can handle what ever miner you get and get proper amount of PCIe power cables (not adapters but cables)