How not to be deceived

[Жар-птица]

Gentlemen, good morning, I begin an art expert (while studying at university). I want to talk to you on an art dealership. Here I have, for example, have a friend, heir to a very serious films (the level of the Tretyakov Gallery). And we want to sell them. Examination is, prevenans clear more or less, no insurance. My further action, advise! Prices now similar pattern superheated. As the market for such antique paintings in Moscow is still mostly illegal, then how not to be deceived ...? To start?