Advice on starting a PC/buying singles in Europe

Basically been collecting for about 2 years now and have a pretty nice collection going but they're all from buying boxes (usually directly at Topps, like I did for the finest hobby, or at Dave & Adam's europe shop)

I wanted to start building a more in depth Manel Kape collection (as I'm from Portugal) like 1/1's, different autos, the country pride card which looks amazing but I didn't pull from the gold label, etc...

My question is if any European fans out there know the best place to buy singles, as buying on Ebay is almost out of the question for me since every single card comes with at least 20-30€ shipping (since they're either US or UK)

I've looked and never found an alternative, but maybe there's some european fans out there with their own PCs who can give some tips.