The decision
Remote staffing can still require additional phone-system seats, EHR licences, secure access tools and time from your internal trainer. List those items separately instead of assuming the supplier's staffing rate includes every part of the workflow.
What to compare
Ask who provides the device, who maintains it and who pays for replacements. Confirm whether candidate interviews, training shifts and replacement onboarding are included. Record recurring and one-off costs in different columns so the first month is not mistaken for steady-state spending.
Before you commit
For an in-house comparison, use the actual local wage offer plus your practice's benefits and payroll estimates. Compare the same administrative scope. A remote assistant cannot replace physical duties simply because a job title sounds similar.