The Indication of Transformer Model S11-10/0.4-800KVA

S11 is the national standard for the magnitude of transformer losses, lower than the S9 loss.

10/0.4 is the high voltage side rated voltage 10 kV, low voltage side 400 volts. And 800KVA is rated capacity.

The price depends on what kind of material you want to wind, and the aluminum and copper are much cheaper than the whole copper. There are also protection devices, insulation requirements, protection levels, altitudes, etc. that affect the price.