The dealers can't keep the prices high, it's supply and demand, when they quite new all the doubters said they would be worth 10k by now.......
I sold my last one for just over 20k, that had a 400+ pack, coil overs, AP brakes, comps, etc, that was 18 months ago, it would still go for the same money now, maybe more.
As for private vs dealer sales, how many people have 20k in the bank to buy a car? Not many, hence going to a dealer you can part x your old car, cat a finance deal and have the back up of buying from a proper supplier if you do get any issues.
I would recommend Focus RS direct, good bunch, they do well because they pay fair money for cars and are easy to deal with. I think there's a bit of jealousy with a lot of people, they see FRSD doing well and don't like it.