If you can create your own compost and also set up water collection (butts etc) this can make it more cost effective
we were lucky in that we recently moved and there was already a well established compost heap and large greenhouse - DH had dismantled all our raised beds when we sold (although has spent money on more!) and our water butts (though again has bought more), plus there was already a well established orchard with several varieties of apple, plums, pears and cherry plus bushes with raspberries, blackberries, sloes and a grapevine.
we are growing asparagus, courgettes, squash, potatoes, onions, shallots, peas, tomatoes, chillis, watermelons, strawberries, runner beans, chard, spinach, lettuce, sweet corn and lots of herbs but I know DH has spent a fair bit setting up notwithstanding what was already here and what we brought with us. We also bought apricot, peach, fig and walnut trees.
things like squashes and onions are good because they store well over winter and you can obvs use for lots of things. And berries/apples to make compots/crumbles to freeze. Definitely salad stuff like lettuce/spinach is amazing in the summer straight from garden and I’d say cost effective as you eat what you pick whereas if I buy a bag half of it gets chucked
but DH does get up at 5 to tend to “his” garden and it is also a hobby for him so he doesn’t mind the time