USA Bee Error Yellow Shift

I have this used bee stamp from the US with the yellow color in the bee shifted a good ways to the left. Is this a major error or is it more rare?

What you have is Scott 2281. There are known varieties where the black or yellow colors are entirely missing from the design, which commands a premium price, however, color shifts are surprisingly common on a number of US stamps -- including this one -- and they bring little (if any) premium over the $0.20 used value listed in the catalog -- even less, considering the damage to the right side perforations shown in your example.

Probably more appropriately classified as as "freak" in that it is not within the intended printing tolerances, yet there is no premium value attached to it either. Still it's an interesting conversation piece to keep aside.

This would not be considered an error; more of a printing freak. The color misregistration, while not common, is only marginally significant if we are considering retail value, especially since the stamp is also damaged. Usually, color misregistrations need to be several millimeters off (or produce an interesting and distinct change in the design), to warrant a premium. There tends to be a fine line between a poorly printed stamp and a printing freak with an increased retail value.

I've seen major color shifts so that the black/yellow parts of the bee are >50% separated, and these typically run $5-$10 retail. Black (engr) missing copies can be had for <$50, in both mint and genuine postally used condition.

Considering the condition and marginal color shift, I would guess that your stamp should retail $1-$2 tops.