AI LLM Subscription E-Commerce Site

I’m building a full-stack web platform that sells access to an in-house large-language-model (LLM). The site’s core is e-commerce, but instead of one-off product sales I need subscription services with clear, tiered plans (think “Starter”, “Pro”, “Enterprise”)... (Budget: $250 - $750 USD, Jobs: API Development, eCommerce, Full Stack Development, HTML, Node.js, Payment Processing, PHP, Website Design)