It's much less than 25 cents per KWH, but I live in Ohio, which is cheaper than Jersey. I got quotes and negotiated with multiple data centers until I got one that I liked, but can tell you for sure that the first quote you get from them is likely to be very inflated.

I was not in a hurry and took my time, and the co-loc facilty I liked the best had a price match policy. I was able to get them to beat a quote from another co-loc facility that offered a good price, but I didn't like as much.

Also, keep in mind that you don't need a gold plated co-loc facility for BTC mining. I haven't had any downtime yet but a little downtime does not bother me too much for the price I am paying, and BTC also uses very little network bandwidth. You don't need a state of the art data center for BTC mining, and I certainly didn't want to pay state of the art data center prices.

I was actually very frustrated with my data center search until I filled out a request at http://www.datacentermap.com. Within 24 hours, I was contacted by three different data centers in the area that I hadn't previously considered, and ended up choosing one of them. I highly recommend that site to start your search.

The main risk with renting co-loc space is the contract length. I had to commit to 12 months, so the first few months of your contract are the most risky. It would be very painful for the price of BTC to crash right after signing a 12 month co-loc contract.

Also, a lot of co-loc facilities require insurance, which is a royal pain in the ass to get for any BTC related business. The big, conservative insurance companies like State Farm and Nationwide will not touch a BTC mining business with a ten foot pole. I had to work with multiple insurance agents, and it took me a couple of weeks, but I was finally able to get insurance through Travelers.

It takes a while, but persistence pays off. If it was easy to make a profit mining BTC, everyone would do it.