I cannot address the real estate purchase issue, but have you driven on the 15 to test your theory? Regarding the remodel costs, if you are your own sub, then I would think you could remodel the kitchen for 50-100K depending on how high end the cabinets, appliances and the flooring, i.e.- marble, travertine, etc.is that you use. The bath I would expect to be less, possibly 25-35. K, depending on such factors as above. My neighbor paid 75. K for his bathroom remodel, but I think he really overpaid and he used someone who advertises extensively, so look for a contractor who needs work, but checks out in terms of no complaints. Ask to visit other places he has remodeled. Landscaping can be a do it yourself project if you do not want a lot of hardscape, which adds a lot of cost to the project. I would guestimate 10-20. K depending on what you want. Good luck.
One more thing, since you are commuting, have you looked at the Temecula area which has good schools and lower prices generally than anywhere, (except Chula Vista) in the San Diego area?
