How much does MERN consulting cost?

Code audit from $2,500 (2 to 3 weeks). Architecture review from $4,000 (2 to 4 weeks). Performance audit from $4,000 (2 to 4 weeks). Security audit from $5,000 (3 to 4 weeks). Technical due diligence from $8,000 (2 to 6 weeks). Virtual CTO retainer from $4,000/month. Single consulting calls at a fixed rate per call. All engagements include a 30-day follow-up call.