Option A: Coda: maps rates, you recompute, it drafts the options table
Best when: Every price needs a visible derivation row
What it does: Coda maps and lays out; you recompute and sign off
Strong at: Docs with tables that sync like databases
Limit: Arithmetic in generated cells needs your recalculation
Free plan: Yes, limited (1 GB attachments per doc)
Option B: ChatGPT: lays out the table from your hand-built basis
Best when: The derivation must stay with one accountable person
What it does: ChatGPT formats your finished figures; you sign off
Strong at: Answers questions; writes and rewrites text
Limit: The derivation work is manual and comes first
Free plan: Yes, limited (file uploads, images, voice, data analysis)
Option C: Gemini Notebook maps rates, Claude drafts with workings
Best when: You want a cited rate line behind each price
What it does: Gemini Notebook maps; Claude drafts; you recompute
Strong at: Answers grounded in the sources you provide
Limit: The rate extract goes to two vendors
Free plan: Gemini Notebook: Yes, limited (500,000-word sources); Claude: Yes, limited (5-hour usage caps)