We own a 2 story KB Home in Murrieta, which we purchased in 2003 for $360k.
We spent about $20k on options — the carpet upgrades were essential — and are very happy with the home. KB has given great warranty service on the few small items that needed it.
It also took at least $20k more for a patio, a back lawn, a patio cover and window coverings.
So, if I were buying a KB home now I would budget $40 to 50k to allow for options and work on the yard.