@Scott Bell I'm doing a few BRRRRs in Burlington right now that come pretty close to meeting this criteria (SF is a little smaller).We've also done a few projects in Wilson and Rocky Mount in the same budget range. 

Even if you found one that was in your price range, and DOES cash flow... you still need to qualify.

I’ve heard of different ranges of appraiser’s views on ADU values, some do treat ADUs as whole other unit in terms of value (other’s add roughly half), just depends on which one I get.

From the few companies I spoke with, they assume somewhere in the 150K range without seeing it.I would hate to have business on the upper floors that cannot accommodate clients that canon use stairs but is a 150K+ expense worth the result?

My budget is 150k-170k  plus 5% closing cost and hope to get duplex with that range.

I've bought used ranges and they tend to work well and last without issue.If you're only interested in buying new, check out Sears.

Mini splits are capable of heating and cooling but they're a bit ugly with the inside units being bulky and noticeable and also they are a bit more of a challenge to service (no central air filter)Does anything else run on propane such as the dryer, water heater, range, etc?

And thats how it was done at least in the SF Bay Area and 5 years earlier homes were trading in the 30 to 50k range.. 

Looking for a house in the range of 150k to 250k with a 50k downpayment.

The 4/2 model we are selling for $275k usually appraises in the $330k to $340k range on pre-construction.