The value of student work

[Иван]

Good day!
Found student works of several artists:
1. Alekseev A, 1958 50h33, Untitled.
2. Dickov, VP, 1957, 35h47, Quay Port Said
3. Jafarov A., 1956, 35h47 Unloading Ore
4. Duzelhanov, Untitled.
Last two authors I found on the Internet, but also that they were /ARE members of the Union of Artists and their paintings are stored in including in Tretkovke, I found.
I would like to hear your professional opinion about these works, whether they represent artistic value.
Possible cost.