The Cleveland 588's are 50-77-93. With the PW of the G25 set at 115, does that seem ok? Dropping 3000 credits for wedges doesn't seem as good to me as getting the Rossa and the L59s for the same price, but I'm willing to be persuaded.
I have to be honest here and say that I think your experience with the putter just happened to be a very good round that you happened to have. I actually used the starter putter until I hit Level 70 and got the Versa. Never regretted that decision.
I'd put a whole bunch of money on a bet that the credits spent on the wedges would be a better investment than the putter. With those wedges (or a comparable set), you'll save a lot more strokes per round (in the long run) than the putter will save you.
In fact, with those wedges, you're really getting about 9 clubs (full swing, punch, and pitch) that are highly effective. Your average distance to the pin will go down considerably. And that means you can make do with a lesser putter for a while. I think the better putters really show their strength when you get to tournament (12) and championship (13) greens