Hi Curdster, welcome to the forum.
I don't think any of the adults on the forum here have a CGM, however I think quite a few of the parents on here have children with CGMs. Some have NHS funding, some self fund. From what I recall, sensors cost roughly ?30 each and have to be changed every 3 days (although I think a lot of people 'trick' the CGM into being used twice and thus getting 6 days out of them).