Thank you for your comments @Thomas Manning, @John Thedford and @Kristine Baker!
We don't have a signed agreement with our realtor, but he's been with us from the start and I want to stay with him for any future sales. I like your suggestion Thomas, I'll just call up another agent and ask if I can offer them something for a CMA.
We are not wanting to sell anything right now, we're just buying out an investor and want to get an estimate of what his "share" is worth. We set up our investment structure as shares of the portfolio, so if someone wants to get out, we need to get an estimate of current market value of the entire portfolio. I realize this is definitely not the easiest or best way to structure a partnership (and I wouldn't do it again), but we started down that road...
This is also why we don't want to hire an appraiser. It would get too expensive and we really only need it for our small group of people, not to market anything to outsiders.
Thanks for everyone's insights!