AI Chatbot with Lead Capture for My Online Store

I need an AI-powered chatbot for my website that can answer customer questions about my products, shipping, and policies automatically - and capture contact info from visitors who show buying interest, so my team can follow up. Looking for someone experienced with AI automation (n8n, Claude/GPT) who can build this from scratch, not an off-the-shelf plugin. Budget is fixed at $100 for a first small build - open to a bigger scope for future work if this goes well.