I really think you're exaggerating the costs involved of a database that takes a note of railcard no, expiry date, email address, and then once a week or so generates a report and form that automatically emails users in the renewal period.
Given that it would encourage renewals, it might end up making money.
The database would need to be built and maintained, at a cost. Staff would need to be employed to key in manual Railcard forms, at a cost. An interface would need to be built between the online Railcard sales portals and the database, at a cost. Someone would need to be paid to verify the database and marketing system's compliance with the Data Protection Act, the Privacy and Electronic Communications Regulations, and plenty of other regulations I'm sure. The application forms would need to be reprinted to state that data may be disclosed to whatever organization runs the database, at great cost. Staff would need to be paid to handle data subject access requests, process opt-out requests from marketing, ensure that customer data was deleted when no longer needed, and so on. Someone would need to build the logic to send out the emails, including no longer sending YP renewal emails to people over age, at a cost. I could go on.
So, I'll ask again. How much more would you be willing to pay for your Railcard in order to fund the renewal email database? And do you think the Railcard-buying population in general would prefer to pay this increased amount, or to look occasionally at the date printed on their Railcards, put a note in their diaries, set a reminder on their phones, or use one of a number of cost-free options?