I'm half joking, but half serious...
If someone from this neighborhood was to cash out and move to somewhere in Peru where houses cost between $8,300 and $21,850 , do you think they would spend much time worrying about the difference in prices?
If someone from another area sells their home and ends up with $1,500,000 in cash, how much time are they going to spend analyzing the difference in your local prices? If the house with the pool is $75,000 more, it isn't going to shock them.
Our neighbors who moved to Maine bought a huge, fully renovated home for $350,000 or so. They were shocked to find such a bargain. I bet the locals were couldn't stop making fun of the stupid Californians.
Or, when speculators are frothing at the mouth, and have the comfort of 103% financing, how much consideration are they going to give to the difference in price? They're going to buy anything they can (whether these are valid sales or not is another topic).
I bet that your value range will narrow considerably as you inspect the sales and talk to owners and agents in different parts of the neighborhood. But, you're bound to reach a point where the market considers the price difference insignificant. In some areas there's a 2% range and in others a 40% range. Past that point, statistical analysis won't be of any use and you'll have to just use your best judgement to select a specific value point in that range. You can't be more precise than the market.