The family and I just spent a 7 night trip in our first VRBO (I'll write more on that tomorrow). What was awesome for me is that my son and I went to the local costco and stocked up. We got ground beef, NY strip steaks, chicken breasts, milk(s), cereal(s), cases of water, pop, paper plates' paper bowels, bread(s), muffins, buns, granola bars and lunch meats all for 8 people, 7 are adults. I'm not even listing everything but it was about $350. An amount that would easily be saved just by eating in for 3 meals.
We then went to a local grocery store to buy the stuff that we didn't want to get in bulk (sticks of butter/diapers for grand kiddo) since we weren't planning on packing anything back with us....we went to a vons seems like a small grocery store chain. We bought sliced cheese, bag of chips, small pack of diapers, small pack of baby swimming diapers, sun screen, frozen pizzas some packs of m and m's, DW's specific type of pop flavor, a few other items and it came to $250 for 3 bags of groceries when $100 more was an overflowing cart of Costco goods.
It might have been cheaper to buy the bigger packs and left them at the home?? Costco is awesome because it provides a great value and I have to shop out of my normal routine to sometimes realize that.