Kim, I look at it this way. How would you like to be treated? Someone has a part that you want or need and you do your best to make things go in that direction. Some unforeseen event happens and your world unravels a little bit. What would you like to have happen to/for you?
But, I see nothing wrong with setting up a clearly understood deal and sticking to that deal as outlined. Each transaction might be a little bit different (since your clearly not running a business) can you say legal issues and taxes? I hesitate to shoe horn you in to one size fits all answer. Some people are just slimy pieces of excrement and choose to ruin stuff for everyone. Good luck.
