I repectfully object against "any putter". I prefer "any putter above 500 crs" because putting skills may not be good enough when those cheapos are available, and in this phase a player would hardly see much difference to the Starter putter while he misses the ding too often.
Me thinks that the Starter putter is one of the best clubs in that bag, along with the driver (except for it's lack of length).
I'd start at level 31 with a 3WD, two wedges at lvl 41, and a putter >500 when you need it, the Rossa is one of the best buys you can imagine, alas only at lvl 55 (72.715 XPs).