Just put them up on ebay. Start the auction at $1 and see what happens. Usually things escalade and enter silly territory rather quickly, but you may not get quite the same levels of insane bidding, because you are based in Europe. Make sure that you put your auctions up via ebay.COM. That way you get the most exposure.
If you wanted to sell to forum members, you most likely would not get the price you wanted. Taking the ebay route, however, is morally sound. It is not you ripping people off (as long as you describe everything accurately and don't overcharge on postage...). Let the people decide how much they want to spend on the cards.
The best option would be, though, to simply open the booster and enjoy the cards. Maybe, you want to keep one sealed booster as a souvenir. And you should not throw away the boxes, either.
I don't get why boosters are so expensive. These prices would only make sense, if you found an RF or an MW in every other booster, but you don't. Most likely you end up paying $15 for
Destroyed Homestead or a
Vengeful Primitive...