At the start of October 2025, I began to track some of the items we buy at least a semi-regularly with sats. The idea behind that is to (more) formally track inflation in sats over time. This is intended as regular series to document how costs are changing over time for some of the things we buy with sats.

While I could use a proxy such as tracking items' fiat values vs bitcoin price or similar, I find tracking things we actually buy with actual sats more tangible. In this context, that means we sent sats out of our wallets. ie. No tracking of payments using fiat rails such as debit card loaded with sats.

We've been spending & replacing for a while now. While we could feel things getting cheaper in sats over time, we never put in the effort to actually track and measure it for specific items. This is what these posts will be about.

We spend a portion of each year in South Africa where we can buy heaps of stuff with bitcoin. So I fully expect to have months without any useful data for the times we are in other places where we just don't have options to buy things directly with sats.

I hope the series will still add some value. Even with those gaps, we should get a glimpse of how our purchasing power changes over the years.

Units: Electricity in kWh, water in kilo liters, phone data in Gb, fuel and milk in liters. *We didn't need to buy more water & electricity in November, so no change available for those items.

As expected, we saw some inflation as measured in sats since bitcoin's fiat prices went down for the many shitcoins including the local one.

Milk went up by 6.2% month-over-month, phone data cost us 8.4% more.

Fuel's drop in sats of 5.2% is interesting. The government dropped the fiat price for November. So much so, we even paid fewer sats per liter.

As expected due to bitcoin costing more fiat shitcoins in November, we paid more sats for some of the items.

I'm somewhat glad I started tracking close to a local maximum in bitcoin's price. It makes it more interesting to see that it can also move against you in the short-term. Although we obviously expect to see deflation over the long-term, the short-term is real too.

That doesn't stop me. I still believe in and follow the spend & replace mantra. Since we always "replace" more than what we spend, the sats we spent in November 2025 were replaced way back in July and August 2023. Contrast that with a hypothetical of spending fiat shitcoins saved in July 2023 instead.

Either way, my medium term goal remains to get paid in bitcoin, so I can finally scrap the "replace" bit.

If something isn't clear, please don't hesitate to comment with a question. I'll be happy to provide more details.