It's hard to say. IS this a keeper league? What costs are associated with keepers? How many? What stat cats?
On the surface and in terms of value, I say that it's a good deal. However, what it means for your stating lineup doesn't seem worth it. In terms of starters you are trading Ramirez and Span for Upton and Peralta. Peralta is the worst hitter in the equation by far and will really hurt your starting lineup. I'd rather start Ramirez and Span than that pair. Of course, you can make another move that makes this worth it, or maybe even find something better on the waiver wire, but this is a classic example of why trades are about more than value.