Hi Rosie, I've just sent my application in so I will hopefully be able t give you some feedback within a month.
The total cost for me was £140 for the application and £5 for the statutory declaration. All my doctors gave me their evidence for free.
As for the evidence:
Medical These where completed using the required form from the .GOV.UK site.
GP - Just stating when I came to him, the HRT and while I was pre-op the GnRH agonists I was using.
Psychiatrist (Gender) – From my gender clinic, He gave a very detailed account of the assessment process and cited various key incidents from my life that gave him the evidence for diagnosing me with Gender dysphoria. Followed by my current state i.e. fully stable and happy as a female.
GRS surgeon – My surgeon also gave me a completed medical form stating the work he has done ( this is a bonus statement and I've added it as proof of a irreversible surgery to modify my sexual characteristics).
Other
Passport – This was my earliest official ID showing the date of issue, and the date I'm using as proof of 2 years of RLE
Deed Poll – Showing the date that I went fulltime.
Professional ID and Log book – This has another very early date of issue, and a running log of dates from issue to present ( proving continual fulltime).
Professional Medical Certificate. – Full medical examination from just after full time, from government agency approved doctor.
Driving Licence – About 1 year in as I lost my photocard and therefore it has a more recent date of issue.
I think between the medical testimonials and the official ID's/documentation that I will have enough evidence for it to be approved. Especially seen 2 of the statement s are from members of the GRC panel!!
Hope this helps and I'll try to keep you informed when I get news.