I think Diego had a very insightful post. It will take awhile for prices to come down to the level that you want if indeed you are looking for a 3000 sf home that is newer. sdrealtor had a good recommendation regarding Encinitas as well as you may find a little more bang for your buck up there compared to Carmel Valley. Again, if you are really stuck on 3000 sf then you may have a challenge finding what you want in the near term.
Your taste in what type of home and location is an extremely important consideration. If you want newer homes and that square footage in that 700k range I would bet a place like Stonebridge will be at that pricing in another two years. Those are newer homes and they are big but they sold for close to 7 figures back in 04 and have been falling fast. This is but one example, even some of the nicer areas of Carmel Valley you have investigated may get there but it will take more time.
My recommendation would be to REALLY scrutinize the incentive package and line that up against the possibility of some different depreciation scenarios over the next few years. If the incentive packages outweigh most of the depreciation scenarios then perhaps you should consider buying. Remember though, once you do buy, do not think you will be able to resell in a year or two if you do not like the home without taking a hit. If you do buy make sure it is a home and a community you really are ready to live in for awhile.
I am not trying to scare you out of buying. People buy homes for more then economic reasons. However, just be careful. At the very least time is on your side… the likelihood of prices racing up again are remote if not nil. We may (in my opinion will) see a little price jump in the spring due to seasonal growth in activity that ALWAYS occurs in spring but it will be short lived. Don’t panic if that happens.