As an aside, Costco has a firm no-tipping policy. I tried to tip a tire shop guy who had noticed a low tire on my car as I was parking and he was shuffling cars around. He firmly refused it. I went and found a manager and told him he had a great employee, and that I really appreciated his noticing and calling out that problem.
Along those lines.....
I paid $280.00 for a battery this week at Carquest. A nice young lady installed it for me. I tried to give her a ten spot for a tip.
She flatly refused it. I need to send a nice Google review their way.
That is actually a great 'tip'. nothing is more valuable than your time.