Awesome outliers like Mickey's aside... I have nothing against speculation (flipping), morally speaking, I certainly have that streak in me - I'm a haggler and I can flip things if I come across a good buy. But in my observation this activity tends to be a "race to the bottom" over time. Resale in general. There's a good reason why supermarkets and other retail stores, gas stations, etc. operate on a sliver of a margin - it doesn't take much to buy low and sell high, so competition drives down the prices (and also comes in forms of service perks, etc.). My example - re-selling audiobooks on eBay. They were on a particular narrow field, where people were willing to pay good prices, but it was very easy to copy this idea, so I watched new sellers join the marketplace and drive prices down. I wasn't the first, but I was early and I didn't set out to outsell the others, priced very close to them and chose to compete by better explanation of the product. There was enough business for the few of us. But new sellers quickly undercut everyone (and themselves), so it was just no longer worth it.
I hope it doesn't come across as pontificating, but the only true "business" is creating value - product or service. Producing. Even something as ubiquitous as a restaurant - yes, there's a lot of competition, but your food, atmosphere, location, service - can all create a unique composite "product" that is not easily undercut. It used to be easy to "start a business". Alas, it's been getting harder, by design, in the last decades. No, we won't get into politics and it's not a rant, but I'm just reminiscing and reflecting.
So to anyone who is in position: "don't quit your day job", but by all means flip any chance you get!
And trade/barter when you can, sometimes that's a way to maximize your finds in a mutually beneficial way. And money you didn't spend on gear acquisition is money you saved and you are richer by that much
