[suicideneil]

Since I trawl ebay alot, looking at this kinda stuff...:

hvmaxx = $180-200
Gmaxx chassis = $200-250
RPM parts = whatever new cost is, minus 10%
3906 diffs = $30 for both
CVDs = whatever new cost is, minus 20%
Wheels and tyres = $40-60, depends on condition (chips, scratches etc)
Radio = make him get his own.
Various other parts like bulks and towers & shocks etc = $40-60, condition again.

If you parted it out, that would be a pretty good estimate I reckon, so make your decision based on that, maybe minus 5-10% of the total cost if you sell it whole to him.