996 vs 986 running costs from those who have owned both

[Boxster_S_girl]

So, I searched on this and other sites and found some info, but not specifically my question.

I want to hear about how the 986 compares to the 996 with regard to running costs from those who have owned both, on cars that are now nearly two decades old from a strictly objective, dollars and cents perspective.

I hope this doesn't turn into a thread of: which handles better, or rides better, or looks better.

I'm curious because, beyond the subjective, I can't imagine they differ much. Both are completely mechanically identical with essentially the same issues. On the used market, they're separated by about $10,000 for like-condition. Maybe things like insurance and rear tires might differ (assuming equal wheel diameter)... While I know the "Porsche tax" is real, is there a "911 tax", a premium in 996 over 986 running costs?

Thanks everyone!

[edit; I should add "aside from engine replacement". I know there's a very wide spread in used engine prices from the 2.5 through the 3.6, if your motor decides to give up the ghost. So, for the sake of this discussion, let's not factor that "worst case" scenario...]