the_lhc:JohnNewman:Price is quite understandable.
They are not going to be selling that many copies and the developers need to make a return on it somehow.
Bull, they should have factored that in to the rrp of the hardware. The Sonos iPhone wasn't even thought of when Sonos released their hardware and yet they've taken their app on without charging for it. Yes Sonos sells more but their unit price is less (thank dog...).
As Andrew said, it is an optional extra and therefore it would not have been taken into account when developing the hardware.
You need to look at the number of units sold (not a huge amount), then the number of owners who also have an iphone / itouch, then the number of those who feel the need to replace the standard remote control with the app. The target audience is not that large.
I'm not sure who developed it, but it is likely to be an independent developer(s) working in collaboration with Naim. Developing software is time consuming, it needs to be designed, coded and tested. By the time you divide the profits between the developers, Naim and iTunes the end profit will need to be worth the developers time.
Whether the market feels that the price is right is another matter. I suspect that a fair few people who want the app will buy one, after all £25 is a dip in the ocean when you consider the price of the hardware plus speakers.
If you have one and you disagree, then just vote with your feet and not buy it...after all it is not essential.