The fact of the matter is without white stones getting to plus 15 means 1. A lot of broken items. 2. A lot of stones used( TONS OF STONES) 3. Pure stones are essential(not super easy to come by). In conclusion the time/effort/luck are worth a heck of a lot more than 3million-10million zenny. Not to mention when you get that high a lvl of pants the ground gets cracks below you and looks insane. I would venture to say +15 pants at lvl 6 may even be worth about 100mil+. I saw +11 pants once(lvl 6) and those were 85mil so im sure +15 would be higher than that