Although officially cancelled at the end of Season 4, a mini-series that is supposed to tie up loose ends will be shown in the US starting 17th October. You can see a (frelling great) trailer for it here:
http://www.apple.com/trailers/independent/farscape/ . Unfortunately the BBC have not yet bought the show, claiming that they "have yet to see a finished copy". Even if that was such a great problem, it seems odd that SFX magazine was sent a copy while the BBC were not. I suspect that the internet connections between the US and the UK will be busy in mid-October!
I don't know about repeats, but I recently picked up Seasons 1 & 2 for �45 each at Amazon.co.uk.