Reading through the previous responses it should become clear the answer is, what are they worth to you? If your buying to use then 5-10 is about right, maybe a bit more for the rare ones. If your collecting them then maybe paying a bit more would be OK. Remember that the tool number, especially concerning the older tools, is just a guide to what they may look like, an average if you will. I have 4 different c-431 from different time periods and each one looks quite different and I do use all 4. I also notice i never have the right size pear shader no matter how many diffnet ones I have.