## Problem Our strategic goal is to enable self-service purchasing and subscription management for any product in our catalog. However, our current purchase flow is designed only for products with a single charge per rate plan, creating limitations as our product catalog evolves to include more complex pricing structures with multiple charges under a single product rate plan. This epic aims to enhance our systems to handle these multi-charge cases, future-proofing our architecture while maintaining current functionality. Initial discussion: https://gitlab.com/gitlab-org/customers-gitlab-com/-/issues/12657#note_2502454735. ## Proposal Implement full support for products with multiple charges in both purchase and subscription management flows: * Create UI components to clearly display all charges within a product rate plan * Develop functionality to handle quantity selection and validation across multiple charges * Update invoice preview functionality to accurately represent multiple invoice items * Remove existing backend validations that currently restrict multi-charge products