I've spoken to numerous home owners that spent months if not years trying to sell their home after bouncing around from Realtor to Realtor, and often a large part of what they were concerned with was saving 1 or 2% on the real estate commission. 

Now, the commission is surely the largest expense of selling, but I always ask these sellers this:

'By listing with a Realtor that agrees to cut their rate 1%, what are you saving when they don't sell you house after 6 months?  You are saving exactly 1% of zero - nada!  Plus, you have wasted your most valuable marketing time while you days on market (DOM) have risen - often stigmatizing your property.'

Not to mention that a properly exposed & marketed home will help sell a home for more - far exceeding any marginal reduction of commission.  So, before you focus on potential 'savings' - think about the cost of not working with someone that will earn their commission and get you a faster result and higher sales price.