I downgraded from the VIP pack last month (I've had it since inception) for a short time as after totting it all up including VirginMobile I was paying nearly £150 all in all. But....
....as Bigred said - you won't get it cheaper than VM. I also worked it out that it's more expensive going with Sky than VM. It's nice to have the extra HD channels with Sky I imagine but I place far more value on the VOD and catch-up service.
I am missing my 20Mb BB though, I just can't be doing with this 10Mb