Remember one thing, investment has risk. It can grow better than what you expected, on the other hand it could be wrost.
In this case, you are paying around US$3600. The return only a prediction, it really depend your choice of fund. In the past, the stock market would go up, although it has down side as well. But for long term, it should be ok. An investment which has 9% return every year, it is a good return. It better than you just keep it in the bank.