Before I even look at a price, I have to see a good uptime, stable networks and good reviews.
Before putting another provider in charge of our network, they control certain aspects such as hardware, network etc. So I need to know they can keep up with my reputation.
Then price is not too much of an issue, if the network is proven to be stable. I like to buy a server, and set it up to be monitored intensly via our backend systems, disk, cpu etc etc, before I take the plunge and putting it into production.
I like to check the support, see how technical savy they are, we don't wan't googlers now do we lol.
It depends on many things, network, stability, uptime, price is not too much an issue.
I rarely need support, so I really only care that someone is there should the network see problems.