Ok, let's start!
Your current GPU has a 3D Mark score of: 590
And ranks at Nr. 187 in the 3D Mark list.
So the Radeon R7 260X 2GB 128-Bit GDDR5 (A R7 260X)
Price: 119.99$ (=96 Euro, currently)
Has a 3D Mark score of: 6160
And rank at Nr. 44 in the 3D Mark list.
So it's an top 50 card in your pricerange.
But since I live in Belgium like you, you're probably going to need to search a bit for this card for this prize.
Ir buy from Newegg and pay shipping. You dont need to pay import tax on a GPU, I'm pretty sure.
So if you buy it from Newegg, you get a little extra!
Free 2 GAMES: NeverSettle Space Edition w/purchase, limited offer!
Edit: I'm talking about the Asus one!
Another edit: This card is also 1 year or so old. And you can get the MSI or Sapphire version too!
Those are always good/fair priced!