I remind us all that a discussion on pricing without the context of grade ... and in this case step detail ... is dicey and just going in circles.
The OP says
Quote:A local shop has BU
War Nickels unslabbed for $12 each
Perhaps this is a great deal .... the term "BU" means nothing in the context of modern coin grading and pricing.
Check out the current Numismedia FMV pricing for Jefferson war silver nickels .... at MS65 and better they are all $20+ coins.
What if a few of these coins at the dealer were MS65+ Full Steps (FS) ... then the prices can go real crazy.
For example ... in my collection I have a 1944-S PCGS slabbed MS67FS Jefferson .... I could sell it tomorrow for $1300 if I wished to get rid of it.
I suggest the OP make a determination of the actual grade ... check for step detail ... and reference a few reliable price guides to make some informed decisions.
We are here to help if grading is not yet a strong suit.

David
Take a look at my other hobby ...
http://www.jk-dk.art