To be honest, there are companies out there that offer ridiculous packages like "unlimited bandwidth" on a VPS, first of all 10mbit unmetered does not mean unlimited bandwidth it means that it's capped off. All those VPS hosts need is a couple torrenting customers and the bandwidth is gone. Now those VPS hosts may try to beat competition of the larger companies by offering those packages at $5/month for like unlimited/unmetered bandwidth, 256 mb ram, and 40 GB's of space. At those rates the server would be sold out by like the 30th customer 30x5 = $150/month, that is if they have like a core 2 duo with 4 MB ram and maybe like a 400 GB raid. Now if they built that server, the cost of the server would generally be around 1.2-1.8 G prices on core 2's have dropped, but in the time frame we are talking about 6 months ago they were running like 2.2 grand to build the entire system with premium ram not the junk stuff. Now if that company is renting the core 2 duo more than likely they are spending over $150/m and if they bought the server and decided co-location was a good option they are spending in the ballpark of $100-130/m not including the cost of the IPs, so for a low level range add on 1.50 per additional IP, $160/Month. They try to drastically oversell to 40-50 customers and trying to hit $200+/m profit on that server the whole time barely making 50-100 profit and taking 1-2 years to pay off the server and barely covering cost.
Sorry for the hack slash format of the post, I will edit corrections in a little bit.