Write to existing customers and check that this level of service doesn't decline once you are paid up. Also ask them how they feel about the performance or speed of the providers' computers. If computers are overloaded with too many customers, or the connection to the Internet is shared between too many computers or even several providers, then no matter what type of connection it is, the performance may not be ideal. You also need to remember that just because you can load the page quickly doesn't necessarily mean that other visitors will experience the same performance. You should always ask existing customers what their perception of the performance is before signing on the dotted line.
Price is the easiest to quantify, but even here there are things to consider.
Find out exactly what the price includes. Many providers will charge extra if your home page is visited more than a certain number of times a month. Make sure that the limits are generous enough. Remember that you will be sharing the server that your home page is running on with several other people and these limits will help prevent someone else's web site receiving so many hundreds of thousands of hits per day that no-one can actually reach your own home page. Also, check carefully what is included in the setup cost.