Upon looking at some magazines I got in the purchase of an MP43, I found two MP45 magazines (unfired/un-used/and still with some cosmoline on it).  I wasn't aware that there was an MP45, except upon some research of a prototype MP45 at the end of the war.  I discovered that some of the mags were marked MP45.  Apparently when the year changed from 44 to 45, some magazine makers stamped them MP45, thinking thats what they were supposed to do (made based on year instead of model number of the rifle).

MP45 Magazine

Does anyone know what they'd be worth?

Must be worth allot! Like a 42 wheat penny

Typical Sturmgewehr magazine prices.  Probably around $300-$400 if they are nice.  The only ones worth more are Mkb42h magazines from what I've noticed.