See Page 28 of the CAA Regulatory Impact Document
Annual check £80 to £140
Biennial check £45 - £67.50 (Don't forget the 50 pence!)
Annual licence £20
So the CAA's low end estimate for annual operation is £122.50
Their high end estimate is £193.75
Do you ever recall a government estimate for electronic equipment that didn't finally cost at least double (cf any military equipment, passports and identity cards!)
So based on the CAA's "estimates" I reckon £200 annually will be optimistic