First, there was the loss of good-paying factory jobs which had been the mainstay of our economy for nearly a century.

Looking at the other factors like income, background check, tenant history, references, etc. allows a more broad view of the potential tenant so you aren't relying on a single factor. I

It doesn't mean it doesn't still have some knob and tube but the safety factor is increased by removing fuses as tenants can mess them up by putting the wrong size in if one burns out. 

With your budget try looking here in SFV - Woodland Hills, West Hills, Canoga Park, Reseda, A lot of new development going on in -North Hollywood/Studio City/Toluca Lake Areas  You could also leave the SFV with your budget and get a "better bang for your buck" - By trying South LA, Palmdale, LancasterI've seen investors play in all of these markets and make money - all depends on your strategy (what type of returns you're looking to make and if you are trying to hold/sell) Also, huge factor is your basis or how much you are buying the property at. 

These HVAC components are similar to other appliances in that one factory will turn out similar units with half a dozen brand names on them. 

I know it probably hurts quite a bit to see this much price escalation this quickly.I know guys have tired to frame in a factory and then assemble  and never really got that off the ground.no question lost opportunity end of the day affordable housing is a dream of politicians for the reasons you state above.

It's in a small town where there are a couple of big factories, and there seems to be no shortage of (single) renters for small apartments...

Older houses that were originally expensive houses are a better bet than lower class/factory worker housing.

Staying within a few miles drive/bike from work is a huge factor I am considering.

The X factor is I am from Brooklyn, NY so i would be out of state investing.