Placing value on park owned homes

I know when some parks are sold the homes are tossed in for almost free to either sweeten the deal or make just make it easier to close and get the deal done. However, when the number of homes becomes large, it becomes more important to place a fair price on the home inventory (or the home contracts). So the question is , what is the best way to place a fair price on the homes? This gets especially dicey when there is a partner buyout.

Consider the following scenario. Partners A and B get together and buy a park. Partner A puts up the cash and partner B operates the park. They have a written buyout agreement that includes getting an independent park appraisal to place the value on the park at the time of the possible buyout, but no solid agreement on how to value the homes. Here are some possible methods:

  1. NADA Appraisal Guide

  2. Same amount that was invested to buy and set the homes

  3. Some depreciated percentage of the invested amount (say 10% per year?)

  4. Some discounted percentage of the retail contract value (70%).

I know that note buyers use seasoning, credit scores, etc to determine what percentage they will pay for a note, but when the contracts are lease/option or rent to own, it becomes more challenging.

Ideas, comments, other methods?