There is a wide spectrum of which buying/selling practices are considered acceptable by each person. Everyone is different. Personally, I am baffled that anyone would take issue with someone finding chips on a platform like facebook marketplace, craigslist, or
eBay, and reselling them here at market prices. These marketplaces are constantly scoured by people looking to make a profit. There are literally hundreds of chippers here constantly scanning these resources looking for chips, either to profit from or to find that lucky score for their own personal collection. Some people have even written scripts and set up alerts to find what they're after. Hunting chips outside of this community is a lot of work, and if you think anyone buying chips from external resources has an obligation to resell them to you at their cost, then YOU are the problem, not them. You want the chips? Then go find them yourself. Too slow Joe? Tough shit. Someone beat you to them. Be faster next time or stop trying/complaining.
That's not to say you can't earn karma credits with people though. It's always a kind gesture to sell someone chips below market prices or to do giveaways or charity auctions. There's plenty of that here as well and you can certainly land yourself on other people's goodwill/PM deals short lists by doing so.
One thing people seem to overlook is the fact that for many of us, particularly for those of us who are indecisive and extremely picky about their chips, we often buy chips just because we think they look cool and might fit into a set or some yet to be determined project in the future. Later, that project begins to take shape and goes in a different direction and some chips are no longer needed, so we resell the ones we don't need. Then, maybe a year later, or sometimes even just a few months later, the next shiny thing comes along and we just have to have that next new set. Well, time to let go of the last project because well, this one is better and I don't need both! Then, another rack comes along and we think, "ooh, those look nice!... BUY!" The cycle repeats. Many of us just keep buying and reselling chips in hopes of falling in love with a few sets. This is especially true if you enjoy putting together a nice mixed set or two. The problem with that approach is that if you never pay attention to what the market prices are for your chips, and you always resell them for exactly what you paid or less, you're guaranteed to get fleeced because the market doesn't give two shits about what you paid for your chips. The market is not your friend. It's also not your enemy. It is what it is and it dictates what all of us pay whether we wish to control it or not. It is completely futile to think you can or should be able to control it. The market will set the prices for whatever that next set is that you just have to have, and if you resell your chips for less than market, you'll eventually lose a lot of money. Money that your family probably needs more so than your "friends", most of whom you've never even met. If we all just respected each other's property for whatever it's current value happens to be (like most hobbies do) then there'd be a hell of a lot less fighting around here.
That said, don't be a dick. If someone posts a great chip deal in the classifieds here because they want to pay it forward to someone for whatever reason, don't buy them with the sole intention of just turning around and reselling them to someone else who needs them just because you can. That's a shitty thing to do. Don't do the shitty things. But if you buy them for yourself to enjoy or for some chipping project and you later abandon said project, I have no issues with you selling them for whatever they're worth in the future, regardless of whether it's 6 months from now or 6 years from now (just don't do it 6 days from now). External resources/marketplaces are a different story though, and are completely fair game IMO. Even if you're reselling those chip finds 6 minutes from now.