I guess we are in different camps about correlation of value across zip codes. I am not saying it is illogical but I don’t agree. I believe that the profile of homeowner can vary drastically from Carmel Valley to Carlsbad so I do not think it is valid to say that since a 30 year old 4/2 in Carlsbad sold for this much, that a 10 year old home in CV should sell for that much.
Regarding Arbusto, I think what you said actually bolsters the argument to price aggressively. Let me ask you, did your clients offer more then 730k? I am not disputing that the sellers may or may not have been motivated however it sounds like a clear example of someone chasing the market. I have had plenty a seller who chased the market and lost more money then they would have if they had priced more aggressively at first. If these people priced in the 950k range or something of that order would they end up chasing the market down? In my opinion, yes, but that is only my opinion. In your opinion no and I respect that as well.
In regards to using a 20% bigger home, as a comp I checked the tax roll on 3935 Del Mar Glen and it is a 4 bed 3 bath home and as stated on the MLS it was listed as a 5 bed 3 bath. So that would imply a den or office of some sort. At the original sales price of 889k that is $335 per sq ft. So 500 sq ft at a sales price of 889k is $167k. I know in your example you used 100/sf or 200/sf. I would assume if you had a buyer looking at the two homes in CV that were 500 sq ft in size differential, but everything else was equal but the price difference was only about $100 a sq ft difference (for that 500 sq ft) you would hold the sellers feet to the fire for the smaller home, or recommend that the bigger home is a much better deal for the price.