To be honest...I would be leary that the price is so low that the level of service would not be there. Ever thing has a cost and when you cut cost to bring in customers something has to go. And in this industry service is where the cuts happen.
For half the space and 1.5 times the bandwith I pay $6.99 a month. I consider that more than a fair price and would even pay a bit more to keep the service up to the level I have recieved over the past 2yrs.
You will get folks to sign up with you, with those prices. Though you will have to think out the cost to you if your customers require a lot of hands-on service. What you really earn could be very small if your customers require a high level of service.