B.C.
I understand it is high end and that a lot of the attachments etc are brand new but buying second hand means no warranty and just from my perspective I could not see myself paying more than $200 for a stroller unless I had to buy a specialty stroller ( special needs stroller for a much larger child)
I would say start by asking what you want to get out of it...$350? And be willing to come down/ negotiate. You would probably have better luck selling it on ebay if you are looking to get more money from it. Do you have any friends who are getting ready to have a baby? Family members? Sometimes that makes it easier if it is someone you know and they are in the market.
Lots of luck!