well you have to have something to show to obtain a merchant account, at least a website, physical address, bank account and that's at minimum.
i can actually help you obtain one, it's an easy process even if it's high risk items or service.
if you're just looking for a way to take money on something you're selling without an online presence or offline physical business then 3rd party payment processors are going to be the best bet. BUT they do now have these mobile apps where you can swipe cards on your phone for a decent rate and if you need to you can punch in the card number online to process it, still 3rd party but less hassle like paypal and the others. Not sure if they are in Europe but google mobile app payment processors and check those out.
A company called squareup is one, they send the part for your phone and you can swipe i believe up to 5 or 10k a day.
However again if it's high risk i would strongly advise to get what you need to get your own merchant account, 3rd party processors can be rough with high risk items and sometimes they may freeze your funds and never give them to you.
Good luck.