Is there a difference between the two ?

Local store has:
Pork Kroger Shoulder Butt for $2,29/lb  and  Frye's Pork Shoulder Picnic for $1.99/lb

I googled it. Different parts of shoulder The picnic is cheaper, but has more waste.
Off to the store to buy some.

I don't like all of the tough fat on the picnic and the extra waste that probably offsets its lower cost.  For some reason, I don't like the flavor like as much either.

I just went to Wally World and picked up two Boneless Pork Shoulder Butt's.
More money ($2.94/lb), but nice not having to deal with the bone when you are grinding for sausage.

2.94 for sausage is a good deal, even if you have to grind your own.

We used to have a place that cures the shoulders for picnic hams. I would buy them all the time. Now I just cure butts, I have one in the  brine now.

I don't like all of the tough fat on the picnic and the extra waste that probably offsets its lower cost.  For some reason, I don't like the flavor like as much either.

Ditto

The skin/fat is nice if you want to render fat  for cooking, need some for in  sausage, or want to make pork rinds, cracklins or whatever you call them.
 I remember taking the cracklins out of the sausage press after we pressed them for lard and a little salt and they were great.