If they shop alot at a particular supply house chances are they'll either come highly recommended or with a warning. #4 your local building inspector might have an opinion on a certain contractor.

We are starting to see additional supply from some companies that may have liquidity issues or are stressed which is allowing us to buy at a little better discount than usual.This type of investing is not for someone right out of the gate as their are a lot of complexities but I a great way to earn cash flow

Generally it comes down to job growth, population growth, rent growth, housing supply vs demand, vacancy, diversity of economy, and landlord-tenant laws. 

I can't imagine many people are offering on those homes, but supply is definitely decreasing here.

However, it has also caused people who were selling to drop so supply and demand dropped together.

Our plan is to purchase and live in one unit while renting out the rest, but supply seems to be extremely constrained in the area.

We have always gone to 200 amp but then again 300 amp would definitely be a plus for a geothermal configuration, or the 240v 3x50amp breakers for a LARGE on-demand HW system or maybe the HVAC of a discreet 'grow' facility :) Admittedly the extra amps would adequately supply the future ADU BUT assuming it's allowed I would be inclined to install a separate meter/feed for that.The $3500 sounds reasonable...the last 200 amp upgrade I did myself ran about $800 in materials as those 'code required' AFCI beakers will 'break' you $$$.

I responded that I was happy to pay her supplies costs and negotiate labor costs.

He paid $260 for the supplies (I have the receipts for tax).

Beside the checking with HOA I would also mention that STR has higher expenses. utilities, supplies, cleaning fees etc. make sure you add all the expenses when you do calculate your number.