Retainer
The monthly fee, and the question of what is actually inside it.
What it means
A fixed monthly payment for an ongoing scope of work. In HVAC SEO it usually covers the website, the Google Business Profile, some volume of content and some volume of links, plus a report and a call. Nothing about the word tells you how much of any of those you are buying.
The number on its own is close to meaningless without the statement of work beside it. Two agencies quoting $2,400 can be three times apart on hours behind it, and the cheaper quote is not reliably the thinner one.
Why it matters in HVAC
Heating and cooling demand is violently seasonal and the retainer is not. You pay the same in February as in July, which is correct for the work and uncomfortable for the cash flow, and it is the single most common reason owners cancel in the shoulder months.
The shops that handle this well front-load the year. Content and location pages get built in the quiet months so the assets exist before the season needs them, rather than being written in August when you are already busy.
How to check it
Divide the retainer by the deliverable list in the statement of work. Ask how many hours a month, from how many people, and what happens to the fee if you pause. An agency that cannot describe its own monthly scope in specifics is charging for availability.
What $2,000 to $2,800 actually buys
Three companies on this site publish a comparable organic number. TradeOps Consulting lists SEO on its own at $2,000 a month, plus $500 for each additional location. Plumbing & HVAC SEO publishes $2,495 for a programme covering one trade, one location, one primary city and ten surrounding towns. Hook Agency starts local SEO at $2,800.
The spread between them is about forty percent, and the scopes are not the same shape. One is priced per location from the start, one defines itself by the number of towns, and one publishes a starting figure that moves with scope.
Below that band the model changes rather than the value. Footbridge Media has run a $249 programme since 2004 with no contract. That is a maintained site and a managed profile against a shared team, and for a one-truck shop it is a real option rather than a worse version of the same thing.