^ You can pretty readily get a "group discount" from a faraway vendor for batch-sending stones if you intend to keep them all -- especially at your price point or below. There is a ton of fixed or almost-fixed transaction cost in the time and insurance and energy and (sometimes) customs. Less of an issue within the US.
Never buy with the intent to sell -- unless this is your profession or serious side-hustle (i.e., you can add value by recutting at wholesale or you can do the "geographic arbitrage" -- like if you live in Sri Lanka and your enterprising buddy lives in NYC). If you are like me and nearly everyone else here, you will be lucky to get 25%. You think you don't trust these commercial vendors? Why would a private party trust you?
That makes perfect sense, and that’s what I was thinking anyway. Thank you!