Lot's of dinosaurs around here...
If your 115 days a season were mostly put on your split, I'd say it's pretty well used. $400 would be a good price for it. If it has less than 100 days on it and is good shape, I'd try $500.
I definitely would not sell it for less, unless you've cracked the rail or have any other significant damage like that.
Shred is spot on about putting it on Splitboard.com. Lot's of splits get sold on that site.