Yes prices certainly have doubled in Holland.
A simple example would be the price of bread.
Prior to the euro era we paid 2 guilders for a normal 600 gram loaf of brown wheat.
Now the same loaf costs around 2 euro's with a conversion rate of 2,20 guilders for a euro.
Same goes for cigarettes, used to be 4 guilders, now it's up th almost 5 euro's and those went up 12% in the last year only.
All prices have doubled now , the only thing that hasn't doubled are the paychecks from the company's we work for, that's still half of what we used to get in guilders