Vortex Viper PST Gen II 1-6x24 FFP (would $560 be fair?)

Looking to buy a Vortex Viper PST Gen II 1-6x24 FFP but I've read it's an old model (2017), so I want to offer $560. Thoughts?<br><br>Edit: Thank you all for your responses. I'll probably offer $600 initially and go from there