Use your 5k and find a decent 1-bedroom condo and put it on AirBNB. 

It's a multifamily property in a good neighborhood with three units and a total of four bedrooms and three bathrooms.

  $200/month divides into the $100K initial negative equals 500 months to recover the initial negative equity.Let's double the cash flow to $400/month.  250 months to recover the initial negative equity so over 20 years.Let's reduce the negative equity position to $50K (which likely is less realistic than expecting $400/month cash flow at that rent point), you are at over 10 years to recover the initial equity position.Now let's do it with all cash, no financing.The 50% rule state $900/month cash flow.  900 * 12/200K = $5.4% or about half of lifetime return of S&P 500, or what can almost be achieved with a zero work, zero risk CD.I see no way that someone who understands the numbers will call this a good investment.Note just because an investment is better than most other investments in a market does not imply something is a good investment. 

When I made some changes to the property and put it back on the market about 15 months later for double what I paid, it was under contract in 48 hours.

Purchase price: $145,000 Cash invested: $15,000 Sale price: $180,000 2017, I tackled my first fix-and-flip—a 2004 double-wide mobile home on over an acre that needed a complete transformation.

Also, each of these two units is 3 bedrooms so it might be too big for traveling nurses/professionals.Does anyone in San Francisco or in general have experience with monthly rentals?

I know for sure that in my area of Texas (well outside of major metro areas), we've seen the cost to build new homes almost double in price. 

I would purchase a duplex (or even better, purchase a SFH with as many bedrooms as you can afford and rent by the room), and then slowly improve the property. 

Triple Diamond, Double Diamond, Diamond; nothing sounds bad) of sales levels, putting it on cards and advertising them.

I carried double the cost on Gas and Electricity to be safe. ==== Projected Income ====**Off Season**-$4,000/Month Rent Period: September - May (7 Months) Projected Income: $28,000**Summer 1**-$8,000/Week Rent Period: June (4 Weeks)Projected Income: $32,000**Summer 2**-$8,500/WeekRent Period: July-September (12 Weeks) Projected Income: $102,000**Optional** (Basement Apartment)-$2,000/Month -Rent Period: Year Round Projected Income: $24,000TOTAL PROJECTED INCOME: $186,000 ==== Operating Cost ====-Mortgage: $84,000 ($7,000/Month) -Utilities: $36,200Gas $6,000 ($500/Month) Electricity $6,000 ($500/Month) Internet $2,400 ($200/Month) Garbage $5,000 (Estimate) Pool $4,000 ($250/Week)Landscaping: $4,000 -Mowing: $2,400 ($150/Week)  -Clean Ups: $1,600 (Spring & Fall)-Weekly Turnovers: $8,800 ($550/Week)==== Legal Cost ====Summer Rental Fee: $20,100 (15% of $134K)Sandwich Rental Tax: $6,855 (15% of $45,700) NET PROFFIT: $38,845.00