I am sure you have likely come to the same conclusions, but I am a firm believer in diversification of knowledge, and hope that maybe I can provide some thoughts that you have (or anyone else reading this) maybe overlooked.For starters, when I search for manufactured homes in any particular area, one commonality I see is that the well-kept, well-maintained ones are usually in 55+ communities.

For starters, your original example has to assume that person #1 put $25k down (125k house, 100k mortgage).

Just a typical conversation starter of where or how to park your money best

So far the $1800 starter pricing seems rough. 

It's a stock conversation starter, a cliché passed among so-called professionals, a nebulous blame-it-all to explain the shortcomings of real estate agents who aren't able to deliver a buyer to a seller, and an excuse offered by greedy loan officers and bank presidents who oversold their products by hyper-inflating the value of their collateral.

So that could be a non-starter for you.Second, @Jeffrey Holst make a great point in that if you're actually selling a property and 1031ing into a new property that you want to own with a partner. 

I love Arlington, its a great area and the homes are still inexpensive enough for good starter home properties.

It would be something like a $20,000 starter investment and then an additional $20k contributed each year.

If you haven't already, get to know a particular market area, such as a neighborhood that has "bread and butter" houses that would be good starter homes, low-crime.

At the very minimum i think purchasing them individually (with individual closing costs) is a non-starter for me.