One can convert the utility-per-researcher into utility-per-dollar by dividing everything by a cost per researcher. So if before you would have 1e-6 x-risk reduction per researcher, and you also decide to value researchers at $1M/researcher, then your evaluation in terms of cost is 1e-12 x-risk per dollar.

For some values (i.e. fake numbers but still acceptable for comparing orders-of-magnitude of cause areas) that I've saw used: The Oxford Prioritisation Project uses 1.8 million (lognormal distribution between $1M and $3M) for a MIRI researcher over their career, 80,000 Hours implicitly uses ~$100,000/year/worker in their yardsticks comparing cause areas, and Effective Altruism orgs in the 2018 talent survey claim to value their junior hires at $450k and senior hires at $3M on average (over three years).