'It's only £73 for a change of licence (ie from UK PPL to EASA PPL) '
Don't think so...
£65 for UK-EASA change + £73 for RT Licence (which only lasts 10years!!) + another £35 if you choose to fly an Annex 2 aircraft).
It is the RT licence which according to the scheme of charges only last 10years I find particularly annoying.