Actually, scrap that… I love the simplicity of building new factories on victory cities only. However, I did use your fixed setup idea for a few things and changed how factories are downgraded, checkout the changes to the profiles in post #1.
As far as I understand, you cannot buy any Factory.
But, is it possible to the initial owner to upgrade an IC to his former status once it has been downgraded in a Major Factory due to an earlier conquest?
If not, then there is no need to provide the price of any Factory, this should be deleted to avoid ambiguity.
I have since moved this topic to house rules, there you will find an updated rule discription that will answer your questions… I’m getting very excited about this idea and I’ll be making a YouTube video this weekend explaining it.