My experience with most things is that a item is worth more when you sell the peices than the whole deal complete.
If I was looking for parts, i'd probably buy a parts truck rather than try and gather the individual pieces.. just because it's cheaper overall.
So if you've got plenty of time to sell it (i.e. you're not in a cash crunch, and don't mind picking it apart) you'd probably make more of your money back parting it out.. but also consider your time is worth money, too.. the extra $500 or $600 you make parting it may not make up for the weird hour phone calls and the numerous trips to UPS or the Post Office shipping the parts.
Selling it as a whole instantly gives you a little larger customer base, and gets it off your property fastest.
