I watched a video that said Costco doesn't actually save you any money, so I did some math on what I buy from Costco vs where I used to buy it from

Car #1 - $260 saved in premium gas (about $0.50/gal cheaper than local gas)

Car #2 - $176 saved in regular gas ($0.40/gal cheaper than local gas)

$292 saved in eggs (2 eggs per day)

$120 saved in food court pizza (1 per month)

$93 saved in bottled water (3 bottles per day)

$36 saved in rotisserie chicken (1 per month)

these are very conservative estimates

also on the app it shows i'm getting $66.12 back on the 2% reward and I still have a few months to go