I had just assumed that you made cakes for a living. You should definitely start up a business. I paid £15 for my DD's birthday cake - it was a small chocolate cake with a Disney Princess 'transfer' and her name/age piped on. The lady I use makes delicious cakes but the ones I have are not as clever as yours. I have seen 'Princess Castle' cakes (more like yours) and they were approximately £40.
My friend is hoping to start her own business. She's had to do a hygiene course and now she's waiting for the council to inspect her kitchen and give her the go ahead. She made my son's Xbox cake which I posted on another thread last week.
Hope you can do it as a business because you really are talented