I FLO every shaft that goes out of my shop. Every shaft save 2 have had definite, repeatable FLO planes.
I'd spend the money. TaylorMade isn't trustworthy. Not only do they tell you that spending money to have the shaft play its best isn't worthwhile, they also tell you to buy a new driver every quarter!
Go into a car dealership and ask a sales rep if you need a new car. Then ask him, should money be no object, if you should have a low end car or a high end one. Get back to me on this one.
Unless you bought it used, I'd take it back to where you got it from and get a new one altogether. If money is tight, don't spend any more!
But I'll tell you that if it were me, I'd get that thing Pured.