The Idaho Falls house you didn’t buy in 2020
A $300,000 house at 2020’s average index level, tracked to 2026 Q2.
The metro index went from 273.1 (the 2020 average) to 445.3 in 2026 Q2, 1.6× its 2020 level. That makes a $300,000 purchase about $489,030 today.
With 20% down ($60,000) and a 30-year loan at 2020’s average rate of 3.11%, today’s equity is about $280,966, 4.7× the down payment.
The same $60,000 down payment, put in an S&P 500 index fund instead (the TSP C Fund, dividends reinvested), was worth $162,437 at the end of August 2026, the latest month the fund has reported at tsp.gov.
Run your own numbers for 2020 →
House figures are estimates for the whole metro market, from the FHFA index. Not financial advice.
FAQ
What is a 2020 Idaho Falls house worth today?
About $489,030 for a $300,000 house, a 1.6× market multiple to 2026 Q2 by the FHFA all-transactions index for Idaho Falls, ID.
Why use an index instead of listings?
The FHFA index is built from repeat transactions on the same homes, so it controls for the mix of what happens to be for sale.
Is this investment advice?
No. This is historical arithmetic for education and entertainment.