Hi Massimo!
Thanks for reaching out to us about this. It's an excellent question.
Right now, our US store is able to partner with a local electronics recycling facility in order to source used parts that can be refurbished for sale. We also carry a larger inventory than our EU store does at any given time, and are therefore able to offer a different selection of parts. We apologize for any inconvenience this causes you!
As long as the parts you need are not batteries, you can still order from the US store. Please be aware that customs fees, duties, or taxes would be charged on international shipments, though, and you would be responsible for paying that additional amount upon receipt of the order. We regret that we cannot estimate the amount of those fees ahead of time, as every country and customs department calculates them differently.
If you have any further questions, feel free to reach out directly to our US customer service team through help.iFixit.com, or by emailing our EU customer service team at eustore@ifixit.com. Thank you!