@NNC for my english ~

I see a space before the question mark...

Oh, you're right ! Moreover, I've been careful for the first one >_<

*scarf?

Yeah you're also right ! I seriously need to review what I write...

I agree with CK on the numbers.

Also, as CK pointed out, the "normal" way to form a question like this is "Don't you...?", but "You don't...?" (the current word order) is fine in spoken English. To me it implies more surprise at the fact that there is nothing cheaper than the "normal" word order.

Oh I didn't know for numbers in the beginning of a sentence :O Thanks!

This is known as a tag-question.
See: http://en.wikipedia.org/wiki/Tag_question
Forty Euros for a scarf, don't you have anything cheaper?

This would be the most correct way.
1 Use a comma instead of a question mark after the first clause.
2 Capitalise Euros since it is the name of a currency.
3 Put the ‘to be’ or in this case ‘to do’ at the beginning of the second clause.
But in conversation nearly anything goes.

Cheers
Heinz

I like the current version, as it matches the French (which also uses intonation and not inversion for the question). Euros is lowercase, I believe.