After the death of one of his characters, one of the PCs in my campaign rolled a new character. Using the typical rules for purchasing items with average character wealth, he decided to buy a necklace of fireballs, type III with his gold.
However, he wants to use 7500 gp to purchase 5 extra 10d6 orbs, so he could reload the necklace whenever he needs to. Buying the extra orbs seemed fine by RAW, but I was under the impression that the chart indicated that a type III necklace is not able to hold 10d6 orbs. He contends that the chart only indicates the maximum number of orbs the necklace can hold, but that doesn't sound right at all to me.
What would the proper ruling be?
"Each necklace of fireballs contains a combination of spheres of various strengths. Some traditional combinations, designated types I through VII, are detailed above."
I take that quote to mean that you can have any combination of spheres in a necklace you like. You're not limited by the types; those are just the most common versions available for sale. In addition, all* of the necklaces in that table have a cost exactly equal to the cost of the spheres combined.
So, the simplest way to handle this is to simply let him buy a specially crafted necklace with 5 10d6 spheres, and the spheres from a Type III necklace.
*Type III is the only one that costs a different amount than the amount of each sphere combined, which makes it likely that its price is an error.