The most accurate explanation is often the simplest and obvious one. We got him because he had been on our radar. We failed with other preferred options and Everton were closing in on him. For once we bought a forward we were looking at rather than end empty handed. I don't believe the outlay on him changes our position if a quality forward becomes available.
Theories also doing the round - he is brought in to replace Campbell and indicate to selling clubs we aren't desperate for a striker any more.
If we can actually sign that forward we need, it will be the greatest window ever.