3 years ago the best model was DaVinci. It cost 3 cents per 1k tokens (in and out the same price). Today, GPT-5.4 Nano is much better than DaVinci was and it costs 0.02 cents in and .125 cents out per 1k tokens.
In other words, a significantly better model is also 1-2 orders of magnitude cheaper. You can cut it in half by doing batch. You could cut it another order of magnitude by running something like Gemma 4 on cloud hardware, or even more on local hardware.
If this trend continues another 3 years, what costs 20k today might cost $100.
Think of it as paying for tokens. The tokens you could buy 3 years ago are better and two orders of magnitude cheaper today. If that happens again over the next 3 years then the tokens you can buy today to do a job for 20k will cost 200.
This isn't optimistic in my opinion. It's not even fully realistic because Gemma 4, which you can run on local hardware, is even better and another few orders of magnitude cheaper. A 20k job today might a few dollars in a few years.
In other words, a significantly better model is also 1-2 orders of magnitude cheaper. You can cut it in half by doing batch. You could cut it another order of magnitude by running something like Gemma 4 on cloud hardware, or even more on local hardware.
If this trend continues another 3 years, what costs 20k today might cost $100.