For the benefit of the English-speaking community in which you are seeking assistance, a translation:
New Ipad
Hello
I want to order a new Ipad because I've had my other tablet for 6 years.
I see at Apple that you can buy the new Ipad Air for 668.50 euros. At Leapp.nl you can order the Apple Air 4 Wifi 64GB for 669.00 euros. which one can I do better. I don't know the differences between the Apple Air 4 and the one on Leapp.nl.
Can you help me with that?
Are you comparing the same model and specification? Prices are different for different internal storage capacities - and are different for WiFi Only and WiFi+Cellular models.
An iPad Air4 is essentially the same - no matter which country or region in which it may be purchased. The only difference between the same model, purchased in a different region, is the availability of some software features. For example, in some middle-eastern countries FaceTime will not be available. As for differences in hardware, Cellular models may have a different Cellular chipset - supporting market specific cellular radio bands.
In the same region/country, devices sold directly by Apple will be the same price in both Apple’s physical and online stores. Apple Authorised Retailers may offer slightly different pricing, but prices are generally consistent between retailers.