Assuming you mean the Iraqi Dinar, the exchange rate sounds right. $30 _US is worth 34,889.81 Iraqi Dinar today:
The Iraqi government has been considering a revaluation of the Dinar for some time now, and investors around the world have been buying up Dinars in anticipation. The GOI's current plan is to raise the value of the Dinar by about 15%, which would give your friend a $3.50 return on his investment.
It's not a scam - currency trading is a legitimate form of investment. Banks and hedge funds do it all the time. But a quick Google search shows that there are a lot of sites offering Dinar exchanges - probably for a hety fee. I'd be wary of these, as there likely are a lot of scammers trying to capitalize on Dinar exchanges.