Just to clear up some inaccuracies, McCovey MLB balls (without inscriptions) that are PSA/DNA certified are going for about $110. Here are 2 that recently
sold for that amount.
https://www.ebay.com/itm/Willie-McCo...IAAOSwE~1cBvPo
https://www.ebay.com/itm/Willie-McCo...UAAOSwa55cFU8E
Again, those are completed sales that actually
sold . There are plenty still for sale on eBay in that price range. in fact, here is a really nice one still for sale for $90.
https://www.ebay.com/itm/Willie-McCo...Zbu:rk:45:pf:0
Yes, the $70 offer was about $40 less than what they're going for on eBay but, then again, a $200 asking price is about $90 more than what they're going for on eBay. It's Scott's ball (well, his friends) and he can ask what he wants, but a $70 offer is not as far off as the $200 asking price. And, for what it's worth, PSA/DNA only charges $20 to certify McCovey autos (not $70).
Good luck with the sale, but you might want to have your friend reconsider his asking price.