I actually think they are cheaper on this board for some reason. People anywhere but this forum are selling/netting good value for their cars. Not sure why everyone on here is lower in price. Let's also take into consideration that no one really sells nice low mileage examples on the forum as it is.
Have you checked out the For Sale board lately? Many folks asking some ridiculously high prices for their cars.
I purchased mine just under a year ago with 33k miles for $33k at a BMW dealer. That was retail price, not private party. I figure that I probably left $1-2k on the table, but had already negotiated $4k off their list price. The dealer installed new brakes, new front tires, and did front wheel alignment, in addition to fixing some curb rash on 2 rims and throwing in new floor mats and professional detail. So they definitely sunk some $$ into the car to get it ready for sale. And it was serviced there too. My car has every single option, built in K40 radar/laser, and full service history. So private party value on my car was probably upper 20's at the time.
Too many folks around here already drank the Koolaid before they purchased their car. I'm happy that I didn't snoop around the for sale section of this board before I purchased mine, otherwise I probably would have felt I was getting a steal at the dealer's original list price. People who educate themselves outside of this board find prices on this board to be very high in most cases.
And I've seen plenty of nice low mileage examples on this board. But some of the asking prices seem insane to me. Many members asking more for their cars with 20-30k more miles than I paid for mine at a dealer. Crazy!