$100M per bitcoin is not infinite, and even if the supply shrinks to a single satoshi, which would imply a price of $10 trillion per bitcoin in your world, that is still not infinite.

Here's a more grounded example:

Let's say it's 1914 and there's only one known passenger pigeon left in the world. How much would someone pay for one more? I'll let you look up the answer, but I'll tell you now that it is far short of infinity.

Furthermore, now that there are 0 passenger pigeons in the world, what is the price of 1? Well, there are proposals to recreate passenger pigeons through genetic engineering and selective breeding. In your terms, supply is 0, and demand is positive, but do you really believe that someone will pay an infinite amount for that one passenger pigeon?

Your model is clearly broken.