I was shopping for a sixline a few weeks ago, and the LFS had 5. Three were in 3 different tanks, and one other tank contained a pair. I wanted the largest one, about an 1.25" long. Turns out it was one of the pair together in the single tank. He was adamant about not breaking them up and wouldn't sell me the one I wanted. He said in all his years of selling fish he's never seen two in a tank without killing each other, and for that reason would only let the pair go. I offered to buy the pair, as I trusted his experience, but asked that since I only really wanted one, that he consider a small discount if I buy the two. He declined, saying that his price was pretty good to start. ($18 per fish)
I said I could appreciate his point of view, but I also told him I was a bit disappointed that he would decline a sale. He offered any of the single ones, to which I replied I wanted the largest one he had, and his reply was, "Your wife wouldn't sell you now, would she?"
I don't hold a resentment, but I'm still scratching my head over his refusal to make a sale.

