If you are looking to sell, price it slightly below market price as that is what gets it moving. There's a lot of boats out there and nobody is wanting to over pay. The book values are way out of sync with actual boat values. All of them.
Like was mentioned, condition is everything. Clean, clean, clean is what sells a boat. If you have oxidation, peeling paint on drive, nasty trailer, rotted tires, etc then you need to be realistic on price.
Craigslist and boat trader are the best for DIY online. If you want less hassle and not needing every dollar then you can clean it and have the dealer sell it and they'll take 10-15% of the sales prices.
If you truly don't plan on getting another boat then throw in the extras. Beware that many boat owners have said this only to come back and have to buy the stuff all over again
I'd keep any tubes, skis, and the extra anchors. Just leave the basic orange life vests and keep the nice ones. I would not want someone elses "clothing" anyways.