The short answer
Who should pay $99.99/yr?
Monarch Money is worth it if you use at least two of its core features: budgeting, investment tracking, shared household access, or net worth monitoring. If you only need one, a cheaper specialist tool may be more cost-effective.
At $99.99/yr ($8.33/mo), Monarch replaces the need for separate budgeting and investment tracking tools. Couples get shared access at no extra cost — making the effective per-person price $4.17/mo. That's less than a single coffee.