Pricing overhaul: determining willingness to pay and tier boundaries

[MichaelKM]

I'm a product manager at a B2B SaaS startup that's about to transition from a single-tier, flat-rate subscription to a more complex, value-based pricing model. We're adding significant new enterprise features and need to structure tiers that appeal to both small businesses and larger organizations without alienating our existing user base. For other SaaS founders or product leaders who have navigated a pricing overhaul, what was your process for determining the right metrics and tier boundaries? How did you conduct customer research to understand willingness to pay, and what strategies did you use for communicating the change to existing customers to minimize churn? I'm also weighing the pros and cons of annual vs monthly billing and whether to include usage-based components.