Kitchen stuff:

1. A good chef's knife. It'll run you around 200-300 bucks, but if you treat it with respect, it will last you forever
2. A mortar and pestle. They're big and heavy, but grinding your own spice mixes is something that will absolutely change the quality of your cooking. A mortar and pestle used to be super cheap, I bought a huge one for 20 bucks a few years back, but they're kind of expensive these days.
3. A decent cast iron or stainless steel pan. Learn how to use it and maintain it, and it will last you forever.
4. Nice dishes. Spend a little more to get something decorative for hosting. People coming together to eat is one of the most ancient social traditions we have. Make it your own experience. I don't even spend that much, I just raid places like Homesense when they're changing their inventory and have bought all my bowls and dishes for around 50-70% off. Sure I only have two units of most of them, but I'd rather have a bunch of cool high quality dishware, than a bunch of boring looking, feels like it'll break while I'm washing it garbage from Ikea.
5. Get some glass tupperware. I have something like 10 pieces that I've picked up over the years and now I barely use plastic wrap. They're great for prepping, they're great leftovers, they can be used in the oven (not all of them, double check what you're buying) and they're freezer safe.

Clothing stuff:

1. One nice black suit. You can go to a shop like Banana Republic and get one of theirs and take it to a tailor to get it adjusted. A custom made suit is prohibitively expensive for a lot of people, and the ones that aren't are usually made from polyester bullshit. Make sure it's a classic fit, don't go for skinny or wide anything as those go in and out of a fashion, but a proper fitted suit will always look good. Make sure it's made from wool, a wool/cotton blend, or linen if you live in a warm climate.
2. A couple of nice fitted dress shirts. 2 white ones, and then the other three can be your choice of color. Before you start going crazy on patterned shirts at Dan Flashes, make sure you have your bases covered. I say this as someone who wears a lot of patterned shirts.
3. 2 pairs of quality jeans. One black, one dark blue. Don't skimp out here, check the stitching, check the quality of the material. Cotton only, unless it has like maybe 5% spandex for extra stretch. Just like the suit, get it with a regular fit, no weird carrot shape, wide leg, bell bottom or anything else.
4. If you live in a cold or rainy area, get wool underlayers. It stays warm when it's cold, stays cool when it's warm, dries out on its own, and is naturally antibacterial.
5. Never buy anything made from synthetics except for a windbreaker or a raincoat. They feel like shit, they make too much noise, they look like shit, they have garbage insulation properties, they straight up melt from heat (I watched someone's $1000 Arcteryx coat melt to a chair that was too close to a space heater; the nearby wool coat was completely unaffected), they pollute the environment through microplastics and by taking forever to biodegrade, they trap your sweat (the wicking away moisture thing is complete 100% marketing bullshit), and if you have sensitive skin they are prone to causing outbreaks and other dermal irritation. Stop giving your fucking money to those planet destroying criminals at DuPont and say no to synthetic fibers.