Which is better in the DFW area?

I’ve previously had a Costco membership which I got for free while driving for Uber Eats during college. Only used it for the food court and gas, since I avoided big purchases.

Now I live in Lewisville super close to a Costco(6mins) and a Sam club(14mins) off the highway. So was wondering which would generally be a better option. I generally still avoid super big purchases, but the Costco brand in my mind resonates more with quality, and i have always found the ones in dallas to be pretty good with diverse products. Have no experience with Sam’s at all. Personally I don’t care about Scan and Go which I’ve read about. I more so care about their members mark brand and the quality of the products they carry in the DFW stores.

Also are gas prices different? Does Costco have better gas? I buy premium for my car who whichever is better or cheaper would be a bonus.

Edit: Also I think Sam’s is doing a $25 membership special? Saw it yesterday but can’t seem to find it on their page today.

I never a membership but have been thinking seriously of getting one. I want to start shopping for my food in bulk and maybe buy some personal items for me. So is it worth it? Is it expensive to be a member? What is the best time to join.

It's just me and my GF and her dog. I'm a frugal person and just buy cheap store name brands. I'm spending about $150-$180 a month on groceries for us at the moment going to Walmart and Aldi. We really just buy staple and cheap items like TP and Paper towels, boxed/frozen foods and frozen or canned fruits/veg, bread etc. We don't buy, except for rare occasions, fresh meats. I know you can get a good deal on their gas, which isnt a huge thing for me as I drive a Prius C and get around 57MPG so i'm spending around 15-20 a week in gas.

I'm just wondering if the 15$ a year (promotional going on now) would really save us that much money, and then it increasing, im assuming, to the regular $50 a year.

EDIT: I should mention I work out of town 2-3 days a week and stay with my parents while working so thats also 2-3 days I don't eat groceries at home.