Computers are like cars. The depreciate as soon as you build them. There is no way you will get anywhere close to what you paid for it.
As
Spyware has pointed out the same parts now cost less I'm sure then when you bought them .
That is not saying you might find someone who would pay that but realistically the price I as a system builder would be looking to sell that system for is more around the $1100 to $1200 price mark.
Typical markup is 30 percent so at the price
Spyware quoted you would be looking at $1231
Now that's a retail estimation and that would also include a 1 year warranty which you as the system builder would be responsible for doing.
If you are not willing to supply that warranty then you have to take that in account on the price and drop the price down to $1100 to $1150.
The person buying the system then would receive all warranty papers and documentation you got when you bought all the parts.
Just a FYI also. I have been custom building and selling systems for 15 plus years now and that markup never works in reality when selling as a private person.