Went to a new lumber yard (for me) that quoted me $6.20/bd ft over the
phone for Cherry. I picked out 4 boards, the guy meausured them,
wrote down the sizes which I handed to the clerks. After he gave me
the total, I questioned the total because it didn't quite seem right
to me. He again said $6.20/bd ft. Not having my calculator handy, I
accepted it...

Well, it turned out I was robbed of about $14 on what should have been
$103 order (I paid $117 + tax).

When I got back to work I looked more closely at the receipt, and he
charged me per linear foot, where he rounded the 5.5" widths to 6" and
the 6.75" width to 7", which commanded an even higher price / LF than
the 6" boards. Total turned out to be $3.38/LF for the 6" and
$3.94/LF for the 7".

It's not worth it to me to drive back there for $14 or for a couple of
extra board feet, but is this typical practice or did they just see a
wood novice/sucker?

These guys were still 1/2 price of other ripoff lumber yards in the
Detroit Area (I went to Public Lumber Co on 7-Mile and I-75, FWIW) so
I would probably go back there, unless of course, this was a total con
job.

What would you do and what's typical practice?