Create a subrule of Probulator Operation called Material Ownership:

Each Material has 0 or more Researchers who are Owners of the Material, and the list of Owners is tracked for each Material. Each Material has 0 or more Researchers who are Users of the Material and the list of Users is tracked for each Material. These lists default to empty.
At any time, an Owner of a Material may add a Researcher to the Material’s User list. Each Owner of a Material is also a User of that Material, but tracking the Owner as a User for the Material is optional.

Only a User of a Material may perform actions on that Material unless the rule defining that action states otherwise. The Probulator may not directly use a Function unless the Researcher using the Probulator is a User of at least one Material that has the Function in its list of Functions.

Each Material has a tracked Purchase Price which is either a non-negative real number, or it is “n/a”. This defaults to 0. As an atomic daily action called Purchasing a Material, a Researcher can reduce their Funds by the Purchase Price of the Material (so long as that Material does not have a Purchase Price of n/a) and then add themselves to that Material’s Owner list. The Researcher performing this action is not required to be an Owner of the Material to perform this action on it.

Assign the following Purchase Price to each Material should those Materials exist:

Test Qubit: n/a
Electron Microscope: 1000
Digital Radio: 200
1980s Pager: 100
Josh-shaped Tamagotchi: 50

Create a subrule of Material Ownership called Basic Tools:

All Researchers are Owners of Test Qubit.