I think MilRob nailed it. Layout/grain flow is number 1. I bought a very nice piece of Circassian Walnut a few years ago because the figure was outstanding. I watched my stock maker saw it into forearm blanks because the layout was dead wrong in the head/grip area to provide adequate strength were needed.
Proper grain flow (think straight) in the grip area is critical. Beyond that, if one wants to keep the type wood as it was when Fox guns were being made, blanks in all Sterlingworths and later Savage made guns (Sterlingworths and A grades) were American Black walnut. Prior to Savage buying Fox, all graded Foxes were made utilizing Circassian walnut. Circassian/English/Turkish are pretty much that same thing for the most part. Higher grade Foxes were made utilizing progressively higher grade Circassian blanks as the grades went higher (A to F grade).
I think if one wants to spend the money for a restock then choosing a nice blank is just the right way to go. Why spend 3K for a restock and utilizing a $100 blank. Doesn't make much sense to me.
PS. When Savage bought at Fox at the end of production even some of the higher grade guns were made using high grade black walnut instead of Circassian blanks for whatever reason. I surmise it may have been done in order to save money, although with the higher custom ordered guns the buyer could specify what type walnut they wanted.