Yes but you could split it out along an 80/20 rule. Where 80% of the value is computed by a simple algorithm. Avg price, square footage, #of rooms etc. Then have 20% submitted by a person. That would still give you a rough idea, and cut it down to hundreds of attribs, rather than thousands.
If and when the owner felt like adding in info on added amenities he could do so for a more complete appraisal.
Yes its still subjective, but so are all appraisals and it would get people closer to where they want to be which is narrowing down wide swaths of housing to a value and range that they are interested in.
