Assuming a $200/mo per property cash flow after PITI, PM, and 15% additional hold-backs you could hold back $20k for initial reserves and buy 3 more like properties tripling achieving the same cash flow as if you had paid cash for 1 property while cutting your risk of tenant default by 65%.

and about 600k, 650k  to build resell at 1.4 to 1.5  we will have the least expensive new build in the city.. the rest are a tad bigger 3.200 to 5k sq ft. and start about 2.2 and go to 4.2  .. then you take SF bay area and you triple it .. in cost to buy land build house and sell price. 

you have one go wonky on your while tenant is in.. contractors would double or triple the price.