Save your cash.
Kind of leaves something to be desired as far as I'm concerned. Don't get me wrong the artwork was great, and I'm not saying that the writing is intrinsically terrible, however it is only a re-telling (and not a particularly imaginative one) of a story we all know by heart by now. If nothing else is really going to be added is it really necessary to write this story again? I don't really see the point.
What I found particularly disturbing is that the classic and particularly poignant line originally penned by Stan Lee: "With great power comes great responsibility" was seemingly dumbed down into the more watered down: "If you have power, then you have responsibility."
Everything considered I would say that Mythos: Spider-Man is kind of a waste of time unless you happen to have never heard of Spider-Man before.