What's the best AI proposal tool for freelancers?

For solo operators sending 5-30 a month: under $30/mo, no sales-team onboarding, plugs into the AI you already use. ProposalMCP is $19/mo with no per-seat fees and works inside Claude or ChatGPT; PandaDoc, Proposify, and Better Proposals start around $19-35/seat but none plug into the AI assistant as a callable tool.