I don't think it is different, apart from any issues with timing of the buying and selling and price changes in between. I think this is more a question that the government doesn't have the gold and buying it from the miners is how they will get it. I don't think they are giving the miners a bad deal, other than forcing them to accept Cedis. I believe the net effect is that fewer Cedis are put on the market for dollars and this prevents a price drop in Cedis.
I'm not sure why this was downvoted. I did leave out one thing - I think the Ghana government is making a statement that they don't want to transact in dollars. That is an important difference, but it is not related to the monetary dynamics.
