Sorry; should have been more clear. As wiggy says I have included accommodation as well as transportation. Hotlines are generally 90EUR return but sometimes more. Rail return to CDG about 36EUR. Accommodation between 30 and 80 depending on how posh I want to be. Say 50 average. So each return commute is about 180EUR. Multiply by 3, 4 or 5 gives 540, 720 or 900EUR. I try to create back-to-back trips if I can.