Ya sou Ellaki - do you have an IKEA near you? are you in Athens or somewhere else?
I know the choice in Greece is not very good, so you might be better to make a cage from a plastic storage box. Ikea sell some large ones but any very large plastic box will be ok.
It is not very difficult to make a cage out of the storage box and it will give your hamster the best space. I know that you will see small cages available but these are not good at all for the hamster, as it needs lots of room. Just because there are small cages available, it does not make them good.
You will waste your money on the Duna Fun. If you have 245 Euros to spend then you should be able to find something much better or make a "poli orea" cage from a plastic box.
Here are some links to Greek online shops with good cages:-
ΚΛΟΥΒΙΑ IGOR
That one is 159,13 Euro and the measurements are very good - 102 x 54 x 38cm.
Αφτος ειναι τελιος (That one is very good)
Ferplast Criceti 69,38 Euros
Ferplast Kios 49,80 Euros
Hagen Κλουβια Μικρον Ζοον- Zoozone 72,70 Euro
I hope this helps Ellaki.