(for developers)How much would it cost to develop a rails app?

I know there is a huge range on how much rails app would cost, Just ballparking, how much would it cost to develop a web app with subscription services for access to video content and email with downloadable pdfs

Really not too much if you want to use something like Wistia for the video hosting. You can control access there and it is about as simple as building a building a blog for the videos, email integration, and file storage somewhere.

Totally ballpark, I'd say depending on how little you could get away with, it might cost $1500 or higher.