Cross Of Valour.

[Al-muell]

Commonly faked, but original pieces are available. Undocumented ones can even be bought for 150PLN If You are lucky, but they are often more expensive (usually twice as much).
A late issue/reissue document (later than ca. 1960) may cost around 100PLN, a doc from 40's/50's - 100-300PLN, a doc of first post-war type (very ornate, similar style to that of e.g. Grunwald Badge) no less than 300PLN and a temporary certificate from 40's (which theoretically is much more rare than the ornate one!) 200-300PLN.
However, I have purchesed Katański's set for ca.200PLN and the doc is from early 50's. Nothing is certain...
1USD=~3,5PLN currently.