Prices and investments in paintings by old masters

[sergejnowo]

Dear forum users,
address the issue, in relation to demand, prices and investment in (a) of the old European masters and schools in Russia and Ukraine at present.
Here's a concrete example:
School of Rubens (Peter Paul Rubens 1577-1640), 123cm x 167cm, with a frame 146cm x 188cm. Conclusion guru Rubens in Germany, Professor, Dr. Muller-Hofstede (Prof.Dr. Müller-Hofstede). He confirmed the school of Rubens, calls the name of the student and believes that the faces of some characters doctored hand of the master. If to proceed from the situation that is all true and the picture presented for sale in Moscow or Kiev.
Can I ask for this picture and say sell for 50,000 euros?
But is it worth investing in this picture?