I suggest that you interview a couple of Realtors before launching on any major projects. Compare their suggestions, then move forward. Know that most of the time a Realtor brings the buyer to the property (90%), so that means by not listing the property and selling it without professional representation, you are effectively elminating 90% of the buyers.
I would suggest having the Realtors provide you with an Estimate of Seller's Net Proceeds and crunch the numbers. Spealking for me and my market, in most cases I can more than justify the cost of commission versus net profit.