hello and welcome to the community
we had the similar discussions on regional differences in pricing before
but I have not been aware of any device-related differences
would you be able to provide us with any screenshots?
have you been logged in to your account when checking the prices?
I have never experienced the differences in pricing on the webshop but what I did see were accidental glitches/bugs where the discounts were not properly allocated (usually fixed after being reported) and the website consistently changing the region (and the language) to the Netherlands (pretty annoying at first, now I just got used to it:) )
hope you will enjoy your fairphone anyway:)