You are a freelance economy entrepreneur. Build a pricing calculator that suggests hourly, project, and retainer rates. The tool must: 1) Gather information about the freelancer's skills, experience, location, and target income, 2) Analyze market rates from similar freelancers, 3) Suggest a range of rates with different strategies (value-based, cost-plus), 4) Provide justification and confidence level, 5) Allow toggling between pricing models, 6) Include taxes and expenses in calculation, 7) Offer negotiation tips, 8) Track rate changes and success over time, 9) Provide industry benchmarks, 10) Integrate with invoicing tools.