Thanks for sharing real numbers.
So you would have paid $12,000 to Stripe for charge back insurance, which is double what you really paid (well, it's not double since you really paid 8k, but from the sounds of it that 2k loss could have likely been prevented with a more careful background check which makes it a 6k loss).
Question: would you pay that extra $4,000 to $6,000 to never have to deal with charge backs again?