Value of used pickups

Like almost anything else, it's about demand.

Most people aren't looking for PRS pickups, so demand is low, and prices are low.

OTOH try selling an original PAF and...

Stick to your guns for a while. Lowballers are everywhere.

I agree its about demand.

Usually stock stuff even from quality companies like PRS just doesn't sell that well although they are EMG's? Are they replacements themselves?

Active EMG's normally sell pretty well but if they are passive...hmmm...list price isn't a good guide, its how desirable they are...

Your bang on in your value and assessment. Don't let them go for much less than half, that's what street price is.

You just need to be patient if it's not a hyped brand/model.
Don’t sell too cheap. Don’t go for less than half of its original price.