Ok, "can't" was probably too strong generally speaking, however I interpreted from the original post that they were not similar but yet no adjustments were made so they were simply averaged. I presume, if the range was so tight, he likely wouldn't have posted a question, but his instincts, based on what he was seeing, suggested otherwise. I was taught that it was good appraisal practice to never average and to apply weight to the comps that most closely reflect the subject. Hell, I once took a class where the instructor wore a t-shirt with "never average" on it. The MAI's I worked with taught me the same. Even if they're close, I'll weight the value.