So I have this Ore Buster lying around that used to be used on diamond ores in my labyrinthine basement a long time ago.. It is still ~91.229% (1425/1562 durability) intact. I am just curious how much it is worth now.. o3o
One way to value it would be to multiply an estimate of the number of extra diamonds you think you would get from each use times the value of diamonds times the number of uses left. That doesn't give the collector's value, of course.
It still has value, but used custom items go for considerably less than they would at full durability, though I'm sure you know this. As MrsWishes stated earlier, you can try to calculate the worth of diamonds it could mine to find a rough price that you could get from it if you were to use it on diamonds. I wouldn't personally pay the 90k that PenguinDJ mentioned earlier for this item at this durability, but that's just my opinion. A close to price perhaps. Depends on how much you could make from it mainly.
90k? I doubt you would even make a half of that if you mined only diamond ore (Only account for the extra diamonds it gives you, not all the diamonds).