Murrieta is built over a Hell Mouth. Rampant vampires and demons.

Besides that, I think the reason it’s cheaper is because the commute to SD is almost reasonable from south Temecula, but from Murrieta it’s out of the question.

I don’t know enough about the areas to know if one is “nicer” than the other. I think the weather is a little more mild in Temecula.