Your question is a bit hard to understand, but I'll have a go.

No, eBay Russia would not exclude International shipping.

Any seller, however, can choose not to post to another country. They can even select which countries or regions they will post to. I don't post outside of Australia and that is my decision, not eBay's.

Given the likely travelling time for anything going from Russia to Australia, except for expensive methods, a seller would likely fall foul of eBay's Money Back Guarantee, which heavily favours buyers, and lose their goods and their money.

To me, the Russian seller who your client can't purchase from has made a smart business decision.