Not too recently I'm afraid - But from memory it wasn't too exorbitant (and we are cheap barstewards, prone to great whinges & grumpiness if it gets too costly)
My biggest suggestion is that you take all your documents & Certs. with when you check in at the 'Office'.
Passport, License, Insurance, Certs of Registration & Airworthiness/Permit, Radio, Oh. Everything - They asked for and went through everything with a fine toothcomb and then photocopied it all.
FYI - Our Route:-
Overnighted in Perpignan (LFMP) - Basically then down the coast to BGR (VOR) - POS (VOR) - VRP "E" - San Bonet (LESB)
Pretty simple really. The weather OK until we left BGR . It was carp on the overwater sector but then improved greatly from about 10nm to run to the island.
Oh Lordy! It was done in September 2007 - 10 years ago!!!!! Strewth!
Have fun
Signed: EGHHZXAC - Life's tough if you don't weaken.