I know the post is 6 months old, but someone replied yesterday, and...I was just looking at S4RSs last night and S2Rs the night before.
I'm thinking $5k if you are serious about selling. Just had a look nationwide, several good looking S4R bikes for $4900-5500. One guy asking $10k-ish but he's dreaming.
And an S4Rt marked as an S4R at $8-ish, but with only 900 miles.
Even a few S4RS bikes for $5-6k.
It is definitely getting close to being the right time to sell weather-wise. Economy-wise may be another story, depending on how the Wuhan Virus thing goes. Good luck with sale.