I'll give it a shot.
The reason I didn't go there is that the gallery owner only presented me with the option of returning it or exchanging it. He didn't address the possibility of my keeping it. He said if I return it, they will destroy it. I don't know what to make of that. I get that they would need to destroy it, because then they would have 101 prints out there instead of 100, but my keeping it would certainly be the least expensive option for them, and involve no hassle. I'd think if there were a benefit to me to keeping the print (i.e., that it has more value), they would suggest that, because they are going to literally travel 5+ hours to pick this one up from me.
I will either keep this one, or exchange it for another, because I do enjoy it and that's why I wanted it in the first place. So it's not about enjoyment. I just have had so many problems with this thing that it's made me not ever want to do business with this gallery again. The thought that they could be literally trying to screw me on top of everything else (by taking back a potentially more-valuable piece of artwork and replacing it with one less valuable) irritates the crap out of me. If keeping the print with the error is to my benefit, I want to take it because of all the hassle.
However, if the print is LESS valuable because of the error, I definitely want them to drive the 5 hours out here and get me a new one.
My point is that they have messed up this transaction in every possible way and turned something special for me into something that has made me angry. I want the best possible outcome for me from this mess.