Well the point is to NOT send a miner to a regular data center since they tend to cater to those who need large server type of data service, with lots of data in and out. We miners only need power (lots of it...) and a little bit of internet data, hence the problem with sending miners to an everyday data center. For miners you want to send them to a "hosting facility" specifically for mining. There are numerous ones that can be looked up here, but I went with Cryptoboreas in Canada and they have some of my miners, and will be getting more soon enough. Alan is a straight-shooting guy, and while he deals with clients with at least and order or 2 of magnitude more hash than I (yes, 10 to 100 times more...), he's been as responsive as if I were too, and will do as time goes on.
Calculating ROI is easy enough. Depending on your hosting facility's pricing, you should be looking at $55-$65 per kWmonth. Compare that to the power usage and expected coinage from a particular miner and you'll know if you're good to go or not.
Just my 0.02
BTC, as always YMMV.
Mine on!