There is no smartest way, it all depends on how you personally choose to balance competitiveness and spending.
The consensus seems to be that there are a few sets that stand out as better than anything available to that point: The lower level R11s, the L59 G20s, the L79 Burners (now Bladez), the L83 G20 woods, and finally the L90 R11s. The Ping Raptures are favorites among players who need a slower meter speed.
There is no consensus on putters. Nearly every one has its loyal fans. I see you've already purchaced a MAX model...don't know much about it, since it hasn't been around long enough to develop a following. I suspect you'll be able to use it for quite some time, if not forever.
Wedges are the best way to improve over the starter gear. Nearly all players ditch the hybrid club in favor of a third wedge. It's far more useful. You spend a lot of time hacking at the green from short distances, and the starters aren't up to the task. For lower levels, the Clevelands have a reputation as the best available, while the Ping Tour W series is known as an excellent value. The upper level Clevelands and ATVs are both improvements over anything else.
Balls will save strokes, but are credit burners - so it goes back to your personal choice regarding the value of strokes for dollars.
One thing to keep in mind is that your progression through the levels will slow down as you move up.
http://www.wgt.com/forums/t/48159.aspx
this thread is the go-to for estimating how long it will take you to unlock gear. It helps a ton when placing a value on an intermediate upgrade.