A landowner contacted me recently whose neighbor wants to buy the treetops left over from a recent harvest. What are treetops worth?
Cutting tree tops is extremely dangerous. The tops are a jumble of limbs intertwined with many bearing weight from the limbs of another tree. If done by a person not familiar with the process limbs can spring back and do major damage to the cutter. So, I would not let anyone onto your property who's not an experienced cutter. I'd also ask the cutter to sign a hold harmless agreement and ask them to show you proof of their health care coverage. If the cutter is a business with employees then the owner must have workmen's compensation insurance, which by the way would cost the business at least $1 for each $1 of wage paid. This is a certain indication of the danger insurance companies assign to this type of work. I assume your liability would be higher if you are paid, compared to "doing someone a favor."
This publication has a formula at the bottom of the tables that can be used to estimate the volume in cords of firewood in red and white oak tree tops. Firewood Volume Tables for Red and White Oak, Iowa State University, Forestry Extension. You could assume an average tree diameter for the calculation. But, no cutter is going to keep track of cord wood volume. The solution is to sell based on the number of truck loads the cutter removes from your property. The volume per load varies greatly. A cutter couldn't pay more than $5 a load and make any money if they apply a cost to their time.
Every landowner needs to consider the risk compared to the potential revenue prior to selling wood from treetops.