My GP's surgery in the UK wants £98 to write a letter about my medical history. Nearly $200. In advance, natch. If I was sure this would get me on to the plan I originally applied for, it would be worth it, as the secondary plan is about $200 per month more than the original plan. The benefits are similar (I'd rather have Better Plan from Other Company which is the same as the secondary plan in price but more extensive in coverage, but doubt I'd be accepted for that if I wasn't accepted for First Plan).
The receptionist was really snooty in her email, too, basically telling me there was no point in bothering (how does she know? has she tried?).