An 11 month median with even replacement means you're buying the sales function, not the delivery function. Price it that way. If they lose 34 clients a year and win 34, every dollar of that revenue costs a full acquisition cycle, and the multiple should reflect a business whose maintenance capex is sales labor.
The question that separates the two is why clients leave. Get the cancellation reason for the last thirty, in the client's words, not the owner's category. Three patterns matter differently. Agents leaving the industry entirely is segment attrition, and with consolidation pressure on the agent population that number is not going to improve for you, but it also isn't a product failure. Agents cutting the retainer for cost reasons after a slow closing quarter is budget sensitivity, and it tells you the offer isn't tied to anything the agent considers load-bearing. Agents saying they can do it themselves now is the one that should worry you most, because that's a price ceiling closing in.
Check the mix of what the $740 buys. If the bulk of hours goes to social posts and property descriptions, you're selling into the part of the work with a free substitute, and margin has one direction. If a meaningful share is photography, video, presentation builds, and website or CRM management, cancellation is more painful for the agent and the 11 months should be longer than it is. If that's already the mix and life is still 11 months, delivery quality is the problem and 55% margin says they're solving it with cheap contractors.
Also confirm who owns the client relationship. If the owner personally sells and personally presents, and 34 agents chose him, the asset walks at closing and no earnout structure fully fixes that.