Two homes on the same street sold recently in Louisville, CO. Both similar in size–one was updated and listed by a Realtor, the other was not updated and not listed by a Realtor. The updated house listed by a Realtor sold for 105% of list price–bidding war situation.
The non-updated house not listed by a Realtor was sold via word of mouth or one of those buyer letters. The non-updated house sold for $90,000 less. If the non-updated house had been listed by a Realtor and put on the market it would have sold for at least $50,000 more than what it sold for.
Make sure to always hire a Professional Realtor to provide a full-service listing when selling your home.
(Disclaimer: I was not involved in either transaction)