I think their best bet would be to find a way to combine that unused space into one of the current units.  

If the house is over 40 years old ( and I'll bet it is) there could be a lead paint issue.

Hello Fellow BPers,I enjoy reading the forums, but there are many times like international trips where I don't have  access to the web, but have time to read.Is there a way I can "download" specific forum topics and read it on my E-reader without internet access?

Depending on the location and whats actually on the land i bet you could lease that out to hunters..Guys pay good money to have access to private land. 

In Silicon Valley doing a web search for "city name comprehensive financial report" will almost always find it for the "city name" you are interested in.

I have looked far and wide across reaches of the web for calculators to to help me predict specific timelines, depending on my investment strategy. ( be it aggressive, conservative or somewhere in between) I found a few, but nothing to my liking, so I made my own.

You'll find everything you need and I bet the results will surprise you!

So to answer your original question: if you want a lower % of closing costs, your best bet is probably to buy someplace else. 

Don't bet on the appreciation and let the vehicle take it's course.

@Jonathan Larios You're best bet would be to invest where people are steadily buying homes.