Advice for collecting in Eastern European country

I believe Mister No (a forum member who is not super active anymore) is Croatian, and he bought most of his of stuff from eBay.

I don't think Mr No would describe Croatia, a member of the European Union since 2013 as 'Eastern Europe', although some older definitions did include some of the Balkan republics.

In fact it is clear from his contributions to a previous discussion of the topic that it is easier and cheaper to import Plarail into Croatia than it is into the UK. Just saying.