German, French and Polish WWII Postcards

[Xan]

A while ago I found a significant amount of WWII postcards my grandmother used to own. Most are completely untouched except for signs of aging, but one of them is a letter addressed to Polish Forces (in English), with a Polish Field Post stamp.

I would appreciate information on if they are at all considered a collector's item and their worth.

I can provide higher resolution scans on request, but I think this resolution should be more than enough.