Many of these companies have cash to spend so they are just taking advantage of low interest rates to put buildings up. 

Is it really possible to build for that low in the Bay Area?

The truth is that, given the low inventory, it's relatively easy to find an all cash offer. 

I also add in all of the potential rehab costs (up to 15-20k rehab estimates), thus utilizing little or no of my own money, nearly completely leveraged.When I do that, the cash flow on these properties become quite low and I’m likely needing to reduce my offered purchase price to make my requisite 100/mo cash flow. 

In my experience, once you start examining operating statements you find that the expenses are conveniently low.

Even if your income never gets low enough or you don't actively participate, at some point the suspended deductions can be applied to the profits when they occur.

In my experience the interest rates for PL vary, I have seen between 12-14% and as low as 8% for experienced investors. 

You might want to check those numbers to make sure that's what you're looking forJust a back of the napkin calc shows that your month net operating income might be almost zero  Asking price $135000 Monthly payment  ~$1600 Monthly income  $1800 Water  $80 Repairs  $100   Total expenses  $1780 Total monthly NOI  $20   Keep in mind that $100 for repairs a month is probably a low estimate and the monthly payment of $1600 includes taxes, insurance, principal and interest.

Unless its new/newly renovated, CapEx and Repairs are too low. 4.

There are a number of "low cost" real estate field trips scheduled in San Diego on most weekends.