I do, if I have an enormous surplus (which happened in only 1 out of like 10 games)
Looking at the things in KBAP, I'd rather get lvl 3 Neatness, buy every item in the game (since money is more than plentiful, even on impossible) and then start breaking them up. In the end, you may end up giving 50k for a lvl 4-5 item that will yield 1-2 runes, while if you decide to buy them, that'll be 100-250k, and if you decide to exchange for them, you are always close to 2:1...
Thanks to my last few play-throughs, I'm really starting to appreciate the Neatness skill, which in general is considered worthless. A serious money-saver and a really good source for crystals and runes, hands down.