The Hunt for ≤$100 Binoculars
For those unfamiliar, great binoculars range from anywhere from about $180-300.
The average person doesn't need them, but I realized I probably did. When you can't get closer to a bird through a swamp, are in terrible weather, or are out in a national park until the dead of night, extra features like waterproofing and night clarity become more of a necessity.
Even then, I was never going to spend that much. No redditor could convince me to.
Despite terrifying market prices, you can get the greatest recommended binoculars for $100 USD or less in North America if you're insane enough.
The Platform
From best to worst, I found the best deals on OfferUp, Facebook Marketplace, Goodwill Online, and Ebay. The more local the platform, the better the results. People who post on sites like eBay likely know that there's a niche of people fiending for a good deal across the net and will put good binoculars up for bidding. The same can be said about Goodwill Online, to a lesser extent.
In contrast, people selling on Facebook Marketplace or OfferUp are aware of its quality, but are usually trying to get it off their hands quick and easy.
Your greatest demographic is middle-aged to old men in areas with outdoor sports. Centering your search on areas high in them might do you well. If you live in an extremely urban area, try and find the places where people with money who only occasionally dip into these things live, and search. They can afford perfomative expensive things to sell later.
Brands
The brands featured on these sites are widely known and available in many stores. Nikons and Celestrons are also known for their camera lenses and telescope lenses, respectively. Vortex, found in Bass Pro Shops and Cabela's, is a brand marketed towards hunters.
These were my best bets, and after enough scouring I was able to get Celestron Trailseekers for $100 USD. You'll have to do some digging to find a good price: Again, people who know a binocular's worth and are selling it in pristine condition will pay extra to shoot their listing to the top.
Having Reasonable Expectations
It's going to be hard to find anything at sub-$65, and if you do see it, probably don't trust it. As with all resellers, reverse image search anything you buy. If you want something really, really good, expect to camp out your platform(s) of choice. You're probably not going to find fancy brands like Zeiss, either, as those people usually go out of their way to buy (and keep) something like that.
Final Thoughts
I'm happy with what I got. They're extremely crisp and help offset my own eye strain. They also make sure I don't bum off my friend's binoculars. Now I don't have to worry about something suddenly despawning while he handed them to me.
This article was written because I got fascinated with the forum culture around binoculars and their weird elitism. Some users that I could only assume had too much disposable income treated slight lens scratches on used bins like they'd render it unusable. That fueled my curiosity... along with the fact I love looking through marketplace sites for the love of the game.