I was asked to follow up to your post. I operate a consulting company, and we cannot compete with our clients. As such, I am not looking for partners in this sort of business, but we can certainly provide the expertise necessary to help you evaluate the opportunity you've identified.

My initial thoughts are that you are extremely well positioned. Presumably you have a great deal of dark fiber which you own or have right-of-use on in the Baltimore market. You've also got a good sized IP traffic base already. These factors, in combination with the availability of inexpensive, already developed datacenter space, should allow you to minimize capital costs on construction, vendor NRCs on connectivity, and operating expenses on IP connectivity.

You've probably got a solid idea of what costs you need to evaluate. Any improvements to the facility necessary, such as power systems (watts/sqft needed in a datacenter environment have more than doubled in the past few years); security; additional fiber from building cable vault / riser rooms; network infrastructure; any needed cabinets, overhead cable ladders, and network and power distribution plant can all be substantial capital costs.

From an operating cost perspective you'll have circuits connecting your facility, on-site technical staff, some GO&A expense for administrative staff, sales persons, customer service, network operators, etc. You will also have maintenance contracts or staff expense for physical plant items such as gensets, UPS system batteries, HVAC systems, etc. There is a lot of complexity here, and evaluating a datacenter play from a whole business perspective takes time and detail-oriented folks who aren't afraid to walk away from something that won't work.

One other thing; you will absolutely want some additional transit. I notice you only advertise routes to Cogent at present, and while their connectivity is fine for most purposes, that is not at all an easy choice to defend to customers when they ask "isn't Cogent bandwidth bad?" You don't want to create challenges for your sales people / marketing effort, and being single-homed to Cogent is one that cannot be overcome with many potential clients.