Well, I've had a change of heart, thanks in part to my wife. So I'll examine those categories once more, but from a different point of view.
We found a preschool, quite by accident, that is much cheaper than the other preschool we had thought about... almost 40% cheaper. This particular school is close to our house, and is in the same facility that the three year old's dance class uses. The drop in cost is manageable when thrown in with the our other monthly expenses. We may have a more difficult time stocking our 'new to us' car fund. However, sometimes you have to make sacrifices.
While our daughter does hang out with the neighbors and various friends, they are typically all from the same background. The exposure to more diversity will be good for her.
Her preschool isn't a traditional preschool. The staff consider the preschool a 'creative arts' preschool. Since we regularly work with her using reading flashcards and various writing tools (the Nintendo DS has turned out to be great for this), it was appealing that the school focused a lot on things like art and music.
You could call me a waffler or flip-flopper for changing my mind, but I prefer to think of myself as open-minded. Plus, the wife was starting to go insane, and she sold the idea pretty hard!