I use PiData SL BD-r's, as I can buy them in in bulk they work out at £0.99 per disc before tax, but even just buying a few spindles at a time they work out less than £1.5 a disc, and most films will fit on a SL disc if you make it movie only and unwanted audio tracks, failing that you can use BD rebuilder to make a very good shrink to BD-25.
I never use BD-9 or BD-5 as I have a large screen and can see blocking on dark fast motion areas when you shrink a film down that far
I never use BD-9 or BD-5 as I have a large screen and can see blocking on dark fast motion areas when you shrink a film down that far