When trying to figure out what market value or a fair price is for a property, Silicon Valley consumers will often look at recent sales nearby which they find online, extract an average price per square foot, and then decide that this is likely to be what a house or condo is worth based on those “comps”.
First factor: the unique real estate itself (how similar are the comps, really?)
Unfortunately, it’s not that simple to figure out that home’s likely sale price or the probable buyer’s value. Homes are much more nuanced than just the average price per square foot. Unless the comparable sold property is truly comparable in every way – similar quality of updating or remodeling, similar location, similarly expensive landscaping – and the timeframe recent, too, you’ll have to try to adjust based on varying factors. (And that’s not easy – it’s an appraiser’s area of expertise. But you may say “those comps had remodeled kitchens, so that may be worth X amount of money”. You would not ignore that big of a difference.) Look at the list of homes below – how much can you tell about remodeling, landscaping, or upgrades from a simple list? Not enough.
Second factor: speed of sale, number of offers
The situation surrounding each sale is likewise quite varied. A property that gets 4 or more offers on day 7 on the market is a different situation than 1 offer on day 43. If you are writing a real estate contract on a home that is getting multiple offers, it’s not going to help you to compare it to a stale listing that sold with just one offer. It’s not just comps: it can be the current competition that largely determines the final sale price of that house or condo.