If you want to sell a plane, complete with engine and servos, be willing to part it out (and put a sign on it to that effect). That means bring tools to take those things off.
So if you have a plane that you just don't fly anymore and want to get it out of the shop, this is the way to go. Bringing back an engine and servos takes up a lot less space than a whole plane, and you can always reuse or ebay them.
And yes, people tend to overprice things. It's too bad haggling is a lost art, but make a lower offer anyway.
Some years ago, a fellow had a giant telemaster kit for sale. This was before they brought the current giant teles back. He was asking $500 for it. I offered him $300, he said no. Later, when I saw him packing his stuff to leave, I offered him $300 again, and he said yes.
So do try to be flexible on prices, especially if you want to get rid of stuff. Leave the sentimental attachments at home.