I just put together this spreadsheet for using comps to estimate the value of a potential property. Have you ever wasted time trying to play around with adjustment amounts to get your comps to all end up around the same adjusted price? This spreadsheet uses a macro-enabled iteration that changes the adjustment amounts incrementally to minimize the standard deviation among the adjusted comp prices. I've only tried it on one property. Please, try it out and let me know if it works for you! If you get a yellow bar in Excel when you open it, you must enable macros to use it. Use this link to go to the related forum: http://www.biggerpockets.com/forums/88/topics/74601-estimate-home-values-to-within-3400