When you do compare mobile homes to built in place homes, remember that mobile homes tend to break pretty easily, its easier to put a hole in the wall or pull off a cupboard door. 

I don't know if deals like that are easily found.Additionally, D class properties typically don't appreciate nearly as fast as B class, so you might be faced with having to put $15K into your $40K property to sell it for $50K over 10 years.

The more challenging part is trying to determine the discount rate on an average life that isn't directly correlated with an easily accessible treasury.

As long as the house is nice and move in ready...you'll easily find a buyer

A 3bed/2bath will easily cost $2,000 or more a month.

City Code Enforcement: Properties that are consistently getting warnings and citations for failure to care for their property could easily be rentals where the landlord is over his head and would take an out, if presented, but can't afford to fix up the place to sell it.

You can find definitions for "down payment" (or "down"), "balloon payment" and "interest only" pretty easily here using the Search capability, which is accessed via the magnifying glass icon at the upper-right of each page on the site.Just for fun, let's work the numbers, assuming the purchase price is $100K:The down payment, which is the amount of the purchase that must be paid at the time of closing, would be 20% of $100K, or $20KThe initial loan balance will be the purchase price less the down payment ($100K - $20K or $80K).

If you goto sold and filter to lowest you will find very very low sale prices.

Which reminds me - it's time to replace the filters!

You end up overpaying for a property in an area where rents typically stagnate (or even drop as property ages) and these areas tend to not appreciate so you cant even easily exit.