During sale of apartment in Russia i used a proxy person. I paid fee (~ 5000 usd) to this person. Can this amount be deducted and if yes - how to do this?
Yes this would be an expense of the sale and would be added to the basis of the property.
Basically your basis is your initial investment + improvements + expenses of sale.
your gain is calculated by gross sales proceeds minus your basis. If you have more gross proceeds than basis you have a gain, if less you have a loss.
To include the 5K as an addition to your basis you simply state your cost basis including the 5K on Form 8949. Assuming you have not depreciated the property (i.e. claimed it as a rental property).
If you have claimed it as a rental property and depreciated it you still get the 5K expense of sale but you would report the gain on Form 4797. http://www.irs.gov/pub/irs-pdf/f4797.pdf
I hope I have provided the clarity you were looking for, please let me know if you have any further questions.
Professional in capital gains and finance related questions