The value is easy to calculate

If a thing’s rental income can recoup the cost in 7 years, Buffett considers it a great business and wants to go all in.

If it takes 10 years, he’s willing to buy.

If it takes 15 years, he thinks it’s cheap but won’t necessarily buy — he’ll keep looking for better opportunities, unless none exist, in which case he’ll consider buying.

If it takes 20 to 30 years, he considers that the normal price range. Anything beyond that, he thinks is overpriced.

It’s a very simple value estimation method. It applies to everything — not just real estate.