How often will that happen? The existing system seems to massively favour keeping existing big companies big. A small inventor can easily ignored. Meaning, there's quite a difference between being right and ensuring a company does the right thing.
Some products (e.g. mobile phones) are covered by hundreds of patents. A small inventor having a huge benefit from patents? It maybe happens, but I really doubt the benefits outweighs the clear damage that patents are having.
What this means is that any practical implementation of an idea needs to be a multi-million dollar idea in order to be worth patenting. Otherwise you're just wasting money.
I.e., a patent that protects you against a later filer, but that’s it.
Patents are meant as a reward for making an invention, the deal being that you get a monopoly on this new invention for a while and in exchange you have to tell the public how to implement your invention. If you could patent known things that would defeat the whole point.
What changed is that until recently the US operated under a first-to-invent principle, so if two people invented the same thing and they both wanted a patent on it, the one who invented it first would get the patent. As you can imagine, proving when you invented something can be quite difficult at times, and the whole process can be messy. First-to-file just means that in such a situation, the first person to file wins, which puts the US rules in line with other countries and makes things much simpler.
The point is that with a patent, the small inventor can go on to raise further funds to exploit and defend the patent if necessary.
I’m not defending the patent system, but saying it’s too expensive doesn’t make much sense.