I bought my '04 Heritage new for $12,399

 

I'd say they are asking a bit much for that 02 reg cab. just done a KBB on my 05 reg cab xlt 4x2 with the 5.4 and it came in with a trade value around 4500 in good condition. Also looked up what a dealer would charge for my truck and miles and it was 7900 average and a high of 8500 if mint from a dealer selling it. Didn't look up private seller on mine but it would be somewhere in-between the 4500 and 7900 mine seems to be and it is 3 years newer than the one you are looking into.