Understand what each pricing model rewards
Per-employee pricing usually changes with headcount. A flat fee can make recurring work easier to budget but may use limits or service tiers. Hourly pricing may fit occasional advisory needs, while project fees can fit defined work such as implementation or a handbook review.
Normalize every proposal
Ask providers to separate recurring service, implementation, data conversion, software, payroll events, benefits work and optional support. Model a normal month and a busy month. Review minimums, overages, annual changes, renewal and termination assistance before comparing totals.
For related guidance, read HR outsourcing costs and factors that affect HRO pricing.