Build a purchase file for 1 to 6 candidate products against the same requirements (same fields as check_choice). Returns per candidate the check with evidence, the cheapest fitting plan's cost where computable, our hands-on test results, unknowns and the vendor handoff with affiliate disclosure; a fixed order that never uses commission; a summary_markdown to show the user as is (it starts with the share link and says whether any candidate has a confirmed fit); a share_url; and depends_on facts so the file can be re-checked later. A feature counts as documented only from the vendor's own pages, never as tested by us. When requirements.modules names a setup ([{id, role}], e.g. a help desk plus a phone line), read setup_check for the verdict on the whole setup (its known costs per currency, open items and the budget for the setup as a whole); each candidate's own budget line compares that product alone.