I'm from Portugal and shipping things from the US to here is EXPENSIVE, not to mention the additional tax applied by customs here. Some other countries also grant me a hefty tax. Where does your merch come from, specifically the keychains?
osu!store is shipping from the US. You can see the costs of shipping during the checkout. (screenshot for shipping to Germany) I don't know what taxes would be applied to you for shipping to Portugal, that might be for someone else to answer.
I am relatively aware of how the customs work here, so I just needed to know where it came from, really. That's sad, though, because I can't order without paying 2.5-3x the original price.
