Ok not that im defending PPV feeds but this is the way it has gone for most countries BB internet feeds. I got an early half price deal for US BB2 last year which cost £7 for the whole series. The feeds started off at 220k but dropped to 150k after the first week.
I was pretty annoyed at that as the thing that got me into US BB was the high quality feeds for the first series where AOL, love em or hate em, laid on mulitple 300k steams for free (5 in all).