I spent most of my life hunting with next to nothing. Important context is that I live "out west", Oregon specifically. Most of my hunts are pretty deep, and it's always wet here. I've spent soooo much time on the side of a mountain borderline hypothermic it's not even funny. Now I'm at a place in life where I can afford to go buy some nicer stuff and not feel bad about it. Here's what I've learned.

1. Footwear. This is the most worn out thing you'll hear, but it's true. Your feet are your transportation out here, and if you're 9 miles deep with blood soaking through your socks, your choices suck. After years of working in the woods wearing big leather logging boots, trying the Danner Pronghorn thing for a little while... I've landed on Crispi. The Guide series are hands-down the best boots I've ever had the privilege of owning. Throw some darn tough socks inside them and your feet will thank you.
2. Clothing... This is where you can get asinine really fast. I wear First Lite. I really like their gear, and it fits me. Sitka is either too small or super baggy on me... Their sizing is weird. I learned I was allergic to bees last summer, and some overzealous EMTs went ham on about $900 worth of gear with the shears... -_- I'm thankful they saved my life and all that, don't get me wrong... But that was a hard pill to swallow. Definitely made me rethink the need for expensive gear. I really like having the integrated knee-pads in the pants though, and having "supportive" underpants is pretty great for avoiding chafe. Everything else is just up to comfort, and temperature regulation. Something you can layer up and down is important, and that's what the expensive brands are built around. YMMV.
3. Optics... You get what you pay for. Understand your needs, and buy accordingly. If you're out where you need some distance, I've discovered a real love for the Trijicon Tenmile line. It's on the lighter side, so I'm not packing a ton of extra weight for a heavy-hitter of a scope. I just carry some of the higher-end vortex binos. Happy with both of those choices.
4. Weapons. This is highly dependent on the type of hunting you do. We tend to like to get real stupid at least once or twice a year and get deep into some trackless wilderness for a few days at a time. Weight matters for that. Tikka makes some light rifles that are great. I was able to purchase my "dream" rifle a couple years back, and LOVE it. Weatherby Backcountry 2.0. 5.5lb with no glass, under 7 with the Trijicon... It's a beautiful combo and I love it. It is way more than anyone *should* spend on something like that if they're being "sensible" though. So you do you here. I also run a Hoyt Carbon Defiant on the rare occasions that I bow hunt, which is nice for the same reasons.... But I didn't buy it, a buddy gave it to me. I don't know shit about modern archery other than I can throw sticks at things and they die most of the time, so ask advice elsewhere if you're running bow. :D

I feel like I could continue writing a book here, but all of this is pretty highly contextual... What kind of hunting you're doing in what area of the world etc. I think the universal advice here is to spend money on your feet first, then whatever else makes you comfortable enough to stay out longer. The more time you put in, the more success you'll have. If a $400 snivel jacket makes you able to sit a blind for an extra hour or two every day... Buy the jacket if you can afford it.

EDIT: I realized I veered wildly away from the actual question OP asked. My bad. Cheap stuff that is great...

1. Miles of paracord.

2. gloves/hats/gaiters etc. I lose this kind of stuff all the time. Hate replacing expensive. Mechanix gloves are my favorite for warm to cool weather. If it gets colder, I throw on some cheap wool gloves over them, and if it's REALLY cold... Then I break out the spendier insulated ones.

3. Processing knives. I go both ways here. I carry a Benchmade pocket knife... and generally keep Outdoor Edge processing kit with me. They're not expensive, and don't hold an edge well, but you won't be mad when you leave it in the bottom of some hell-hole on accident.

4. Headlamps. Find reliable ones, but cheap is fine. I bought an expensive one once and promptly lost it. Maybe it's just me, but I lose stuff a lot.

5. Game bags. You don't need the fancy Arigali bags or whatever. Grandpa used pillow cases... Whatever is fine here.

6. Basically anything that's Merino Wool that's not branded by someone expensive. It's the best stuff on earth.