Know what you're looking for and you could save a lot of money
Stocking a kitchen can be expensive. Just ask anyone who's ever limped through the first month of living in a new apartment with a two plates and a coffee pot. Assembling what you need from traditional sources can be expensive, particularly if you're invested in getting certain brands for certain things. But if what you need is something simple—a bunch of mixing bowls, a spatula, some tongs, some sheet pans—then follow the advice that anyone who's worked in a resturant will give you: Ditch the big box stores and go to a restaurant supply store.
In New York City, there's a concentration of these places along the Bowery in Manhattan, as well as some scattered around other boroughs. But you don't have to live here to have access to a restaurant supply store—if your town has a restaurant, there's probably a restaurant supply store somewhere. And if not, there are online outlets too, like the wonderland that is Webstaurant Store.
Why a restaurant supply store instead of a home store? Because, first and foremost, they're cheap. You can find many essential kitchen tools for much cheaper at a restaurant supply store than at a Bed, Bath, & Beyond, and they will be just as functional. If you've never been in one, though, it can feel pretty intimidating. There's a lot of equipment you might not be familiar with, and things of radically different sizes, and perhaps you'll feel the need to flee and just pay double somewhere else.
First: don't flee. Breathe. Just like with grocery shopping, go in with a list of what you need. This isn't just to keep you on track, but also so that when you run into an item you can't find, you can ask someone who works there and they'll direct you to the resturant equivalent of what you're looking for. Like if you need sheet pans, what you'll actually looking for are called half-sheet pans because a full sheet won't fit in most home ovens.
The restaurant supply store is, generally speaking, not a place to look for homeware brands. Depending on where you go, they might carry Le Creuset or All-Clad, but you're probably going to be looking at pretty functional versions of items for the kitchen, rather than ones that are for home consumers. That is totally fine—if it works for restaurants to make their beautiful food, it can work for you too. It also helps me to write down an approximate size of things I'm looking for, since you can go so big and so small at the restaurant supply store that a sense of scale sometimes eludes me. I once walked out with a truly gigantic bowl that barely fits in my kitchen (I use it for punch). A stack of metal mixing bowls in various sizes, by the way, is one of my favorite purchases for various uses all around my home.
If you're looking for specialty tools for certain applications, like baking or pizza making, you might also need a little help getting to the correct area of the store. But once you do, oh boy. Restaurant supply stores are full of specific kitchen tools that do things very well, like pizza paddles and pastry tips and wire racks and gigantic storage containers. Once you get the lay of the land a little bit, the options are endless. And if that all sounds just way too much? Again, Webstaurant is the way to go. Pick up five pounds of rainbow sprinkles while you're at it.