Honestly, unless your roos are rare, I really doubt you're going to get any buyers. There are always free roos available here and I usually pick up a few from folks to put into freezer camp if I'm low on eating chickens.
I would put an ad on Craigslist for free roosters, unless you can't stand the thought of them going to freezer camp. My last roos were actually feather legged marans, so rather than butcher them, I gave them away to someone on this list here in Montana. I figure they would improve her lines. I kept one because that bird will go to my main pen and darken the eggs of some of my other chickens.