Average GMAT Prep Time?

I agree with BB on the time frame he suggested. There was a thread on here a while back (I couldn't find it for you) but it was a poll on how many hours people spent on GMAT prep. While a lot of people (in the past) said that 100 hours was more than sufficient, the poll figures suggested that many, many people studied for 200 to 250 hours and even some over the 300 hour mark for this exam. It really highlighted how different people can be because there was some people that studied 100 hours or less and achieved a score of 700+ while some people who studied 200+ hours were struggling to reach the 600 mark....................

So you get the famous answer to your question: it depends.