It also doesn't seem like a good idea, since you are putting your home on the line in an attempt to make money.Chasing quick appreciation and being fully leveraged puts you in a situation where things can go badly very quickly.It isn't unusual for transaction/holding costs to end up being 10% of the sale price. 

I'm not sure if its different in different areas but I purchased a stove and fridge from home depot up in West Bend, WI for a rental. 

That's pretty unusual to me, but nothing too high that I noticed.

There are other aspects to determine values, like buying a car previously owned by some celebrity for example, or antique and collector valuations, but these unusual valuations apply to unique assets, not just any old trailer.There are aspects of "market value" in that legal definition of a buyer and seller having equal or similar knowledge, each dealing in good faith.

It is not unusual to see an entire block assessed at nearly the same amount with homes of various sizes, age and curb appeal.

Its hard for an appraiser to find good comps if a house is unusual.

The $500 minimum premium is not unusual.

Would these be unusual addendums to put into a P&S agreement?

I don't have facts and figures, but it's not that unusual for a duplex owner to use management.

It's difficult to comp since it's an unusual property.