Buddies price = $80, don't know if that includes shipping. My pro shop many times can't get balls for the same price. So, assume $90-100, add $40 for drilling and 10-15 for slugs/grips, so $150 isn't out of line.
While I'd love $107, it's not realistic for most people. Assuming you're getting the ball for Buddies cost, you're only charging $5-10 for grips/slug, and $20 for your time for drilling? You're either doing a large volume, or doing people a big favor.
--------------------
Telling it like it is.