If you know someone is a domain mover and you want to make a connection with that person. Would you offer to them a domain for a 60% / 40% of the sales price?
Getting creative with your deals is what will get you to sell more domains, so offering 60/40, 50/50, or any other percentage to make a deal happen is always a good idea.
I have at times when brokering domains, requested the help of top brokers and offered to take much less in order to learn more, and get the deals done. Just did one like that a couple of months ago with ?.