how much is my macbook worth

wanting to upgrade and looking for a resale valuel or even a website to help.

i dont know what all info you need but here it is:

Model Name: MacBook

Model Identifier: MacBook4,1

Processor Name: Intel Core 2 Duo

Processor Speed: 2.1 GHz

Number Of Processors: 1

Total Number Of Cores: 2

L2 Cache: 3 MB

Memory: 1 GB

Bus Speed: 800 MHz

Reads DVD: Yes

CD-Write: -R, -RW

Write Strategies: CD-TAO, CD-SAO, CD-Raw