It’s because people don’t see the 10% as a lot. They go: $10 to $11 is nothing without realizing that it compounds. Try it yourself: pow(1.1 [110%], 7.27) ≈ 2. Every eight years, the price will have more than doubled.

Ok, $10 to $20 isn’t a lot. But what about 3 decades down the line? That’s now $174. You maybe could afford the $10 (maybe even $40), but could you afford to pay that every year?