At 40 leads a month the build that earns money is a stage pipeline, a task engine that will fire a reminder eleven months out, and one or two text sequences. That is maybe six to ten hours of configuration work for someone who knows the platform, not a 6,000 dollar engagement. Lead scoring on 40 records a month is decoration. Scoring needs volume to calibrate against, and you can hold 40 seller situations in your head better than any model will rank them.
What you should insist on is data structure, because that is the part you cannot retrofit cheaply. Decide now what a record is. If you buy land and houses, and some of your sellers own three parcels, a contact-centric CRM will make a mess of that unless properties are their own linked records. Migrating 2,000 historical leads later into a corrected structure is where the real bill shows up, usually a few thousand dollars in cleanup and deduplication.
The risk you haven't raised is texting compliance. Consultants sell speed-to-lead SMS builds and often leave carrier registration and consent capture to you. Rules on consent and on registering business messaging vary by state and by carrier, and unregistered traffic gets filtered or blocked, so confirm in writing who is responsible for that piece and where your consent language comes from. A licensed professional should look at your consent wording.
Spreadsheet plus calendar genuinely works to about 300 open records. It fails when a second person touches the data. Hire the consultant for a scoped configuration with a written build document you own, and skip the retainer until you have someone else answering the phone.