How much do you tip commissary baggers?

Kind of an embarrassing question for how long I’ve been in. 90% of the time I go to the commissary I’m just picking up a few things after work and hitting the self checkout.

Occasionally I’ll head that way for a huge grocery trip and use a bagger. I’ll get cash back and usually just give the bagger $5, but lately I’ve been feeling like that’s not the best amount. In my head it makes sense; $5 seems like plenty for the 5 to maybeeee 10 minutes total I’m utilizing their services. But I don’t know what else I’d tip. Tipping a percentage on a $200+ cart seems insane