You could buy the Redwood ZB putter for 600 credits now, or wait for the Nike at level 51. The Nike's big advantage is a slower meter, but the ZB is not unmanageable. But, alas, the Nike is 1500 credits, slober, moan . . . take your choice. A cheap, 64 credits a sleeve ball like the WGT G12 - S will slow your meter down and add some spin. I used free balls until the Master tier with no regrets.
PS: My real tip is buy the Daytona putter at level 55 for 725 credits, a bargain!
sj