Setting up the sheet
Take one column per provider and one row per item. Build the rows from the union of both proposals, not from either one alone, because the items that appear in only one quote are exactly where the difference lives. Include every task, every frequency, consumables by type, periodic work by item, any daytime attendance, and the labour hours assumed. If a proposal does not state something, mark it as unstated rather than assuming it is included.
The unstated cells are the most valuable output of the exercise. They are the questions to send back to each provider before deciding. Most will answer within a day, and the answers frequently move the totals more than any negotiation would. This is also the point at which you find out how a provider responds to a reasonable request for clarity, which is useful information in itself.
