It might've been said before, but you get what you pay for. Anyone who will sell you 200 or even 100 gb of bandwidth for 10 a month is either overselling, which will not make you happy, or trying a bait and switch tactic on you. Be careful what you pay for, and in my opinion, go with a dedicated server.
BTW, why would you need so much bandwidth? Unless you are a reseller, or have a VERY high traffic site, it will serve no purpose to you.