Comping: how do you handle figuring out comps and FMV?

[John Blythe]

I'm 1000% sure this is answered about 1000000x over throughout all sorts of threads on here, but am not getting the information I'd like from my initial search and review.

I'm wanting to know what methods different folk employ when trying to figure out FMV, particularly regarding comps. Do you _only_ go through a realtor? Do you trust Zillow, Redfin, etc. for a general range/expectation?

I'd like to run more analyses w/o having to blow up my realtor with so many requests, but don't want to make too many assumptions when all I have is Zillow, Trulia, and Redfin at my disposal.

I'd love to get access to the MLS to save them the time required for this part of the process, but it seems as if getting into the local RE chapter is a pre-req, is that correct?

Thanks for any insights!