Well, by Polish Eagle I'm assuming you mean a Vis 35 Radom.
Only a few thousand were made with the eagle stamped on the side before Germany invaded.
These guns typically show the highest levels of fit and finish that can be expected of just about any mass produced firearm.
It's been awhile since I thought about these (I have a German made one, with decocker but no takedown latch)...
I seem to recall that the Polish-made guns came both cut for a shoulder stock, and without the shoulder stock cut.
I believe that those with the shoulder stock cut bring higher prices, as there are fewer of them.
I haven't kept up on the prices lately, and don't know if any have been imported into the country lately, but prior to the fall of Communism $1,000 for one in even moderate condition would have been a good price.
I'd say check the latest edition of Blue Book of Gun Values.