Customs BTW

It's really very simple, used goods are not exempt from taxes.

You can import shit, and when the sender prices it at 55 Euro, then you will pay customs.

The limit for non-taxation is 22 Euro, I believe.

On the other hand, €55 is the (21%) BTW on €262 so, unless you can find some reference to €262, you have every right to query whether there has been a miscalculation.

In the original question which seems to have vanished, the friend that sent the goods "correctly" valued them at 300 Euro. My friends have always been rubbish at finding "correct" values.....

Either:
2nd hand goods within the EU have had BTW paid on them at some point. From outside the EU, that's not the case. => BTW is due.
Or:
You bought it from a trader => not a private sale => BTW due.

If it's from outside the EU, which it was, it makes no difference if it's private or not.

If it was indeed a gift, then hopefully the sender ticked the appropriate box on the customs label.

Unless the item has been sold through an auction before your friend sent it to you and a market price has been established, your friend is an ... well, sorry .... idiot to note 300 Euro as a value. He should offer you to pay that for you.

Rule of thumb: idiots pay twice, once to the Belgian mafia and another time for their own idiocy. ;-)

Marking the item as a gift would have been pointless, makes zero difference to any item valued at 45 euro and over. But yea, with friends like that.....;-)