A decent discount. My worry would be the huge depreciation that BM's suffer. You can already get a fully loaded new shape 320i M Sport will del miles on a 69 plate for £30k. That's £40k car with nearly £9k gone already. And a 3-year-old M140i with sensible miles, auto and 5 doors can be snapped up for around £20k...
I did get a PCP quote from the dealer I visited for the test drive.
From memory a £39k car (that dealer didn't offer me the discount, CarWow did) after 4 years and 32,000 miles was worth 15k. Can't remember the deposit amount on that quote.
I've yet to sit down and look hard at that - from memory VW Golf residuals were a LOT higher.
Its one of the things I need to do before I drop the hammer on this.
When you are playing the PCP game, its all about cost of ownership - for example, my current GTD actually costs less than an equivalent(ish) Astra over three years...