RWD is intended to stay in your wallet, but it may also be used in the game. The devs are known to tempt you with all sorts of in game purchases for RWD. It's usually a gamble if you're going to get the value you're looking for out of it, so read all the fine print before spending some of your hard earned cash.
Just for completeness, RWD may be located by begging parents, siblings, grandparents and other relatives, friends, neighbors, inheritances, welfare programs, or jobs. But, we all know that with the amount of time you've got to spend playing this game, there's not enough time left for a job, so make sure to ask everyone you know nicely and explain how important Iron Maiden and Legacy of the Beast is to you.