I used 5.2% of the full price to include mortgage interest, taxes, insurance, and cost of capital (ie lost return from an alternative use of the downpayment.). Then I added HOA if applicable. You can mess around with these assumptions but it won’t really change it much.
I ran the numbers for a 2/2 union square low rise condo downtown, a 3/2 with a standard lot in clairemont, and a 1/1 near UTC. For the condos I was able to find comparable recent sales with the same floorplan in the past 3 months. For the house I used an average of three rentals and three recent sales.
Further confirmation is the very low inventory. Anecdotally, seems like the percentage of listings that are estate sales or renovated flips of recent estate sales is higher than I’ve ever seen.