According to the website the models are still referred to as the R9 and R9s
http://www.rohrbaughfirearms.com/products"This handgun is available without (R9) or with (R9s) sights."
As Richard said the actual markings on the pistol will only be R9 for the more recently produced firearms.
It would be up to the seller to properly title the auction and properly the describe the firearm for sale. I did find the auction and from the photo is clearly has sights. Of course hindsight is 20/20, right, now that you know what to look for.
I also noticed in the one photo is the Rohrbaugh literature which has R9 and R9S on it...
Welcome to the forum Bill. While you may be disappointed in that it wasn't what you expected, I don't think you will find the sights a nuisance or hindrance to carrying and/or presenting the firearm.