WGT does offer cheaper balls.
Why continue buying what you obviously consider an over-priced product? Many might consider that Ridiculous!
Having tried some of the black, slow meter balls, I didn't find them anywhere close to being worth the price for me, and didn't buy any more of them.
How much are the green fees at the real course you would play those real Pro v 1s? Most WGT courses are free to play. We get to play courses for free that have some pretty stiff green fees in the real world. We won't even consider real world travel expenses to get to all the courses.
If you use up a dozen Pro v 1s balls in 10 rounds of real golf at $30 per round, you effectively have to add $300 to the cost of using a dozen Pro v 1s balls.