$18 per month for DVDs and streaming still not a bad deal
With the local Blockbuster costing $4 to rent one movie that needs to be returned in 3 days and the added streamed content, it's still not a bad deal.
Anything higher and they could keep it.
Via Redbox that's 18 DVD rentals per month... not including all the free offers you'd also get. Granted this does not include streaming but I have cable and hulu for that.
Personally, I don't think there are 18 movies put a month that I'd want to watch. More like 1 or 2 (and I don't go to theaters).
If you want to watch shows on demand simply invest in a PVR. It would pay for itself very quickly.