In France it will cost you 200 euros for an online trademark registration with up to three categories and 250 euros for a paper registration.
A category refers to types of activities for which you wish to protect your trademark, for instance toys, clothes, musical instruments, cosmetics, etc. Extra categories will cost you an extra 40 euros each.
To protect your trademark, you can fill in the trademark online registration form on the INPI web site. If you're intending to register a patent, the INPI is also the place to go.