I've never had things like this before, but this is strange.
Yesterday, I received an e-mail asking me if i wanted to buy 5000 dilithium for £12. I'm like woah! Then again, don't know about these stuff or if it's dangerous to attempt that offer. I don't see how they can get away with it.
A lot of currency sellers are shady at best. Consider this one: There's no way to directly trade dilithium, except through the anonymous exchange, so there's no way for them to get your currency to you if you pay.
Also, 5000 dilithium at the current exchange rate is about 12 C points, they're asking rather a lot more than that.
Using money to buy anything in game outside of the approved source (C-Store) is not only against the EULA, it is also very dangerous. Besides, at that price, you could get more on the Dilithium exchange by buying $12 worth of C-points.