Open Question: If I sell my mobile home through an assumable note,Can the relator charge me a percentage on the home only ?

The land was sold separately as through me.I will be the lean holder.So the balance that was owed for the total sale price [72,000] for the house and land.I will finance 47,000 on the land note.Is the Realtor entitled to a percentage of 72,000 or 47,000 ? [ I think assumable note is the key word.]