I find it very interesting how every last pro-Russian shill said Berezovsky was to blame right after Litvinenko died...==
It is because he is the one who benefits from this scandal. He is teh master of provocations and hates Putin. It is just the motive.
Second thing he had the access to Litvinenko who inturn was his minion. It is opportunity.
The polonium 210 he could buy here. Link: http://www.unitednuclear.com/isotopes.htm . The price isn't big: $69.
That web page appears to be a spoof.