250 gigs for $3.99/month is overselling.
Ask them how much bandwidth they will give you if you buy a dedicated server from them paying more than $150 per month. Answer will be 2000 GB or some thing like that. This is because that is the price. They sell 250 gigs for $3.99/month only because they know no one is going to use that much. If you do, they will be hosting you at a lose.