At our shop the Attitude new retails at about $219 drilled, while the Sidewinder new is $150 drilled.
Like charlest said, you don't want to insult a friend, BUT you'll incur at least $80 to plug and re-drill them both combined. I haven't any idea on shipping, but maybe another $30 there... so offer him around $100-$110 and you'll probably feel okay.
As a comparison, our shop sells a used ball fairly cheap, but we'd sell the Attitude drilled for $80, and the Sidewinder around $60 drilled. Each would be resurfaced before leaving the shop if needed, too. Most of our customers would not incur shipping costs, so that's the unknown. These prices assume they are both only slightly used. Some of our used equipment is priced at our drilling cost, literally, just to keep them from piling up. Hope this helps.
--------------------
Lane Carter, Strike Zone Pro Shops - Salt Lake City, Utah
Brunswick Amateur Staff