Err.. hate to burst the ranters bubble but where on earth are you paying over £20 for a film?
The biggest films around at the moment are the likes of The Dark Knight (£15.99), Hellboy 2 (£13.98) etc
The comparative standard defs are only 2 or 3 pounds cheaper at the moment so its nowhere near as bad as it was. The main difference is how quickly the prices fall after release, DVDs drop to under £10 pretty quick whereas BD seem to stay up although that also seems to be getting better with the likes of Play offering quite a few at £9.99 at the moment and the many 3 for 2 offers.
Obviously we'd all like the prices to be exactly the same but with any new technology you're bound to pay a premium for a while but to say they are over £20 is complete and utter tosh.
If you are paying over £20 perhaps try learning how to use that new fangled "Internet" to buy your disks?