I have a self imposed rule - don't buy a knife I wont use. And I stick with that...except...
I had long admired the Sage 4, though it was down the list of folders to buy, until I saw it discontinued and bought one before they disappeared.
As soon as I took it out of the box I was smitten. OK, it's just a production back lock, but this thing is just flawless. The fit and finish, smoothness, lock up, centering, the way the blade slowly falls under it's own weight when the lock is pressed, everything about it is magnificent. It strikes me as a highly functional and beautiful work of art.
And since then all I've done is admire it, fondle it, wipe it down and put it back safely in the drawer.
I don't want to scratch it. Weird, as I don't feel like that about any other of my 30 odd folders, even those with very nice custom scales.
Maybe I will get over that one day, carry and use it and let it develop 'character'. But so far I just can't bring myself to do so.