Tim, there are a couple of considerations, however typically I would advise assigning as high a value to your POHs as possible. I do not work in tax or law however, so take my suggestion with a grain of salt.
- Assigning a higher amount to POHs likely lowers the allocation to land (can't depreciate) as the underground infrastructure has a more concrete value (no pun intended).
- Real Estate Taxes: assigning a higher price to POHs may yield a lower assessed value for real property and thus a lower tax bill. Even if you are on the hook for personal property tax as well, I hope you plan to sell the homes in which case that tax goes away once you sell them.
- If you eventually sell the homes, assigning a lower value to them may cause you to recognize a gain on the sale. It would be best to avoid paying capital gains on the sale of the MHPs.
There are likely some considerations that I'm missing, however I hope this helps.