As someone else here has pointed out, the cheaper you price your services, the harder (in most cases) it gets to support the customer, and it's for that reason you should always bear in mind that usually 'you get what you pay for' (I say usually - there are obviously some cheaper providers out there providing a better service than some of the more expensive providers).

This also works with dedicated servers too, so it's probably not best to just go with the cheapest reseller or dedicated server -- if you receive poor service from your provider, you'll struggle to provide much of a better service to your own customers, so ensure you choose a provider with a good reputation!

If going with a more reputable company means forking out a few extra pounds/dollars per month (which it most likely will do), i'd highly recommend you do so -- it'll probably save you a lot more money in the long run, and make life so much easier for you!

I'm not going to dish out any company names here, but lets just say that i've tried servers from various cheaper providers in the past (purely for personal use -- certainly not for my business), and more often than not i've found the level of service to be absolutely appalling to the point that it couldn't even cater for my own personal needs (which were pretty basic). Trying to use the servers from such companies for business use would have been a complete nightmare!

I'd make finding a good, solid, reputable provider your number one priority, when you are just starting out!