There are even Airbnb proprietors who rent out improved and permitted shed conversions for as much as $100/night.  

Is there some rule of thumb regarding how much one should spend on a rehab? 

If you purchase an older building & do nothing to improve it you won't be able to command the rent or maintain the value. 

I'm just wondering what some people's rules of thumbs in the region are for like flipping or rents.Bigger Pocket guidelines are usually like 70% rule of thumb for flipping and 2% test for BRRR.The Bay is kind of a special child, so was wondering what kind of numbers people look for here?

The more you have the more you can lend...the old "it takes money to make money rule" BUT...if you borrow OPM and lend it out then you can use theirs to make the spread.

If you accidentally take out too much, no rule says you can't pay a mortgage balance down during a refinance. 

It sounds like it use to be a little clunky back in the day, but has improved - but couldn't find any recent discussions on BP about Rent Monitor specifically.  

It appears the units are below market, however with some cosmetic repairs and perhaps some capex's I feel I could increase the rent by at minimum (based on local comps) 68%.I would offer 85% of list and estimated $20,000 in repairs/upgrades (this is probably a generous estimate - the property appears to be in good shape, basically needs a face lift).With all these figures, including the 50% rule, financing with 20% down @ 3.5%, I come out to a profit of $262 per unit and a cash-on-cash return of 9.53%.So, does this seems reasonable?

We also knowingly gave up a critical backup exit strategy due to HOA rules, and then needed them when we were having a hard time selling.

if I go by your numbers 54k purchase price amd 24k for rehab  that's 78k you're going to rent 2 units for 750 so that's $1500 a month.you should calculate the expenses taxes ,insurance,maintenance etc and see if the cash flow will make sense.. you can use the 2% rule which in this case looks like you're right on the money. . so if 54k and 24k are right numbers and this is not a complete war zone were you would get your $1500 every month with no problems than this should be a good deal..check again for the rehab costs with a local contractos ask to have written estimates. also see if you need to pull permits.. these takes time and money. .good luck!!