iPod Red with dark Red wheel worth?

iPod Special Edition U2 512GB Red front with slightly darker red wheel. Serial Number 8K140T629ZU Model MC297LL Version 2.0.4 PC It has color screen. Black back cover has U2 signatures in it n iPod Special Edition U2 than 512GB in rectangular line under that serial no. 8K6435HMW6O Designed by Apple in California Assembled in China Model No. A1136 EMC No. 2065 rated 5-30V 1A Max 2006 Apple Computer, Inc. All rights reserved. Works great, What's it worth?