So, I have a hole in my collection for Scott 2274a, the Special Occasions stamp from 1987

Well, as my family was driving to the grocery store, we saw the stamp store was still open. I sent the wife and kids into the stamp store and told my wife to get me a booklet while I ran to the grocery store.
I came back out, loaded the car and we went home. Then my wife tells me "I didn't know the thing was going to cost $20!" I was floored.
The thing goes for $5.00 on
ebay, and I was willing to pay a few bucks more than that for the convenience of having it now, but $20 seems outrageous.
I don't really want to return it, since it was bought properly.
Every retail stamp store I shop at in my area all use the Brookman catalog at their selling price. I've never seen anyone negotiate a price. Is this common with other stamp store? The isn't as high as Mystic ($26.00), but its still more than I expected to pay for these stamps.