We have  thousands of cities and towns spanning a land mass significantly greater than US.

In my observation, they are often past the peak of their useful life span.  

People shouldn't buy a primary residence if they plan to move in such a short time span.  

I'm curious if that's the case.I started the listing at $2,400/Mo. and when that got over 100 views with zero inquiries over the span of a week I dropped it to $2,175 last Friday. 

The span does not look that long, and to me seems like something an LVL could easy do.  

If the load is too much for a 10' span with cheaper material, your options would be to run wood/metal the length of it to add support (joining to another load bearing wall assuming there is one) or to add a support beam in the middle.

Of course not to say this is the deal breaker, but rough math tells me that with ourselves living in, it probably won't cashflow well with big chunk of rent going to mortgage payment.So I started to enlarge the span a bit and visited some properties in Truro since I heard it's the 'Hub'.

I know you have transaction costs but picking a location and a property long distance in a short time span is going to max you out even if you didn't have kids and weren't going to school.

Some hoods we own in, our sold and for rent signs span blocks and blocks.

Hopefully this period doesn't span a long time.