Volume. Logo and numbers stamped during the production process unlike custom logos added after production. If they had to do single orders of custom numbers, they would never get enough mass production to make the ball affordable. So many ProV1's that they can small batch special numbers occasionally and stock them waiting on requests. Tour the Ball Plant and you will get a better feel for what I am saying.

sigh Same reason I can't get a logo or custom alignment marks on a yellow AVX.

Dale, I thought in an email release it said that you could custom order the new AVX with "your" number on it. Maybe I misread it as I was a little excited to try it out this year.