This can be a problem for some people, but based on the comments I've read in the years I've been reading this site most people are in favor of paying huge taxes. Let's say you pay 75% taxes, what is the problem? When you die, the state will get the place and sell it someone else that wants to pay for it; again, and again, and again. You kids will have to work and pay to get it, for the state is just $$$ profitssss. Good business.

It’s not the state which is the problem, according to my siblings. It’s related to the family of who they might have bought from.

Again, I don’t want to give specifics. I don’t want to spread false certainty about how a legal system I literally cannot read does or doesn’t work.

An "interesting" fact of Spain is that all unwritten inheritance goes to the state, and this includes foreigners. Therefore, makes sense to lay down 200 bucks or so in lawyer fee and write the inheritance asap.

No, that's not true at all. Please read the Spanish Civil Code, starting at Chapter 3 ("De la sucesión intestada") to see what's the order of heir prevalence in case of "unwritten inheritance".

Only in the case that there isn't any relative, or widow, or widower, the State will get a 'abintestato' inheritance.

Thanks for correcting me and sorry!

Interesting, but untrue.

Exactly

In some areas of Spain, the state gets to keep a high percent of the inheritance, they go up to 50% or maybe more in some places.