Old films to purchase

These guys have stuff that Play.com and Amazon.co.uk don't. No connection other than as a satisfied customer.

It's also worth trying eBay.com (as opposed to eBay.ie).
 
I heard that Laser on George's street is good for old films, it's close to the entrance to the arcade
 
There used to be a great DVD shop in Andrew Street that had loads of old and foreign films.