It's worth the gas and maintenance you would save alone. 45 miles is a bit of a hike to go to work. I'm lucky enough to be able to bike to work (around 3 miles). My 2008 RX-8 has 21k miles on it. A not so frugal car that sees frugal use. When I go I typically stock up on frozen precooked chicken and other frozen goods like vegetables etc. They have a better variety as the purdue and tyson crap you find in most grocery stores is just nasty. It makes taco's, stir fry, etc so much cheaper and easier. I forget the brand name but the precooked chicken I get there has more than 3 times the quantity of the bags at walmart and tastes much better (No random fatty bits etc). Canned goods and paper products as well obviously. I've got some sinus/allergy issues as well so I always get my pseudoephedrine there. I pay 99 cents for a pack that would cost me around 13 bucks at every other store I got to. You can't order that on Amazon. If you throw a cookout you've got cheap booze, cheap (high quality) meat, and they have a lot of unique brands of snack food you don't find in your grocery store that are insanely good. There's also the $1.50 hot dog combo and samples I get every time I go. I don't eat much junk food but they are so filling and cheap. I often find myself going to the grocery store when I'm hungry and this keeps me from making impulse buys on an empty stomach. Tires are sometimes cheapest for me there as well. I do my own oil changes and I get oil there cheaper than walmart. There's also the large purchases you don't really think about till you need them. I got my TV there. I could honestly go on and on. Buying in bulk really saves me from frequent grocery store trips.

I calculated the cost of my prime membership versus what I would have paid in shipping. I found I saved $300 something after subtracting my membership fee last year in shipping as well as enjoying the streaming service and the free ebooks. I absolutely hate shopping and buy all of my clothes online. If they don't fit right I just return them for free. I'm constantly complimented on my wardrobe. No clothing store can compete with the selection or prices Amazon has. Better selection and prices on most tools as well. The reviews are really helpful as well. I don't have hundreds of reviews on a product in a conventional store. Honestly both amazon prime and costco are worth it. The trick is buying strategically.