How manage different prices depending on deliver-to

Hello,

I have some items that depend on delivery location have different places, but they are supplied by the same supplier-site.

I could source different item prices using NO-GLOBAL Blankets, with supplierA-siteX and supplierA-siteY, but... what can I do if It's the same supplier ans site? ASL form doesn't allow create different attributes if it is a duplicate SITE.

Thank you,