I want to go shopping for groceries elsewhere, but I always find they're more expensive and have a smaller selection. Where do you shop and how much do you spend?

Right now, I spend about $130/week for a family of 3 (2 adults and a 4 year old. How much more will my total be if I'd go elsewhere?

So just recently I was gifted a Walmart Plus subscription to help me with groceries since I have so little time these days. However I have been hesitant to use it yet because I am unsure of how the order procurement and tipping should work with it. I see some places say to tip 20% of the bill but on a $200 grocery bill that is an extra $40 which is quite expensive for me. My main question is who is the tip going to? Is it just the driver? Is the delivery handled by a third party company like doordash or are there Walmart employees that transport the groceries? Should I base the tip off of the grocery bill or not because I am not sure if I am tipping based on the delivery or the entire picking of the order. I don't want to be a cheapskate but also can't afford to tip too far above my means these days. I should note I live in a cheap part of the country without much traffic, not a major city.

I'm trying to get groceries through Walmart+, and facial tissues and ham were out of stock. This isn't the first time they've been without basic grocery items. I've had to have them shipped in the mail, or I would have to shop at another location, which is not very frugal in my opinion. I'm not sure what the point is. I have no issues finding such items on Instacart.