I subscribe to Cinemark Movie Pass for $12/month and every additional ticket is another $12. I also get a 25% discount on concessions which definitely causes me to go the theaters more than I otherwise would. That’s with inflation because a couple years ago it was $8.99 not $11.99 so more but not unreasonable in this market. I wouldn’t go anywhere that charges more than double unless it’s a special occasion or location.
I also subscribe to Cinemark Movie Pass, and it's well worth it. My family loves going to theaters, so I also get a lot of points. Now and then, I can redeem points for multiple free tickets. It won't be an "XD" movie, but I don't see a difference. Plus, we get one free movie ticket every month that rolls over. Very much worth it for avid movie goers.