Sometimes it’s difficult to find and purchase some post stamps on the territory of the country, so there are international auctions where you can buy not only foreign stamps, but also post stamps of the USSR and even the Russian Empire. Such auctions offer detailed consultation, expert opinion and an accurate analysis. The auction takes place in real time. You can make bets through the Internet and by phone from anywhere in the world. Also you can offer your own rare clean or cancelled stamps for sale. Usually the organizer takes about 10% of the stamp price. So if the auction has accepted it, you can be absolutely sure, it will definitely sell it. But if there is an exception, the commission will not be taken. Until the buyer receives the stamps, organizers offer free insurance. To see the catalog of post stamps and take part in the auction, you must register on the web site of the organizer. In catalogs you will find unique post stamps of the world on any topic and year of issue, including the post stamps of Russia of all historical periods.
Philatelic auctions:
Status International - http://www.statusint.com
Auktionshaus Felzmann - https://www.felzmann.de/
http://www.pugachev-studio.ru/ - Pugacheva philatelic salon