What would be a good incentivizing strategy to prevent over spending on hardware? I can think of giving a budget and the amount not spend is payed out to them (but when the salary is that high it might not make sense) or like having a internal dashboard where everybody can see every body’s spending on hardware, so people feel bad when they order to much.
Probably better to just request an unreviewed but detailed justification, and then monitor spend and police the outliers after the fact (or when requesting above an invisible threshold, e.g. any fully-specced Apple products).
The outliers will likely be two kinds:
1) People with poor judgement or just an outright fraudulent or entitled attitude. These people should be watched for performance issues and managed out as needed. And their hardware reclaimed.
2) People that genuinely make use of high end hardware, and likely have a paper trail of trying to use lower-end hardware and showing that it is inefficient.
This doesn't stop the people that overspend slightly so that they are not outliers, but those people are probably not doing substantial damage.