I thought the same thing, that's why I didn't check the box because I already have a diver, but if that's the case then not a bad price for a diver.I did the same on the SnP, I checked the -12.50 box and realized when I checked out that the price was lower. I now think that box takes the diver out of the SnP, I thought checking the box added it.
I didnt want to loose my cart so I paid diverless.
I believe I screwed up.