I have to agree with a couple of the replies you've already gotten Slater, Namely to save your credits until you have enough to get what you really want.
I would suggest however, that you might want to consider purchasing 1, possibly even 2 more wedges ( a 60 deg. and a 56 deg.) and definitely get some decent balls, which will help you out tremendously. As you advance in tiers, you will find that the distances increase and the greens get slicker, and good balls can help alleviate some of this. While the free balls have the advantage of being free, they will not allow you to control your shots, which will become more and more important, especially at the Master/Tour Master/Legend tiers. The Srixons would probably suit you the best (I have a friend who swears by them{he's Legend tier]), but the higher end WGT balls would also work.
GL to you.