This question already has an answer here:
I have someone who wants to put strings onto a private blockchain. He thinks it will be safe for his data. So the idea is to store names and addresses etc on the blockchain (private).
I did some testing and hit a lot of gas limits.
Is there a way to effectively store strings in volume onto a private blockchain and to avoid gas limits?
This is really a design question not a strict cost of storage one.
Various people stated this is a duplicate but I already tested now and one aspect is mining time lengthens with a high gas limit. So that is a factor. It is not simply about cost. It is also about usability.