Honestly, I'd go with "nah". Are people really going to shell out $500+ for this? If someone wanted the parts, they'd just buy the ones they wanted off of BrickLink or eBay, where they know what they're getting in advance. Or they'd get discounted Lego sets, or even garage-sale-style bulk lots from Ebay which are cheap as dirt.
My AT-AT is about comparable at roughly 5000 pieces, which would cost ballpark $500-$1000 these days (assuming it was new gray, not old gray, or some other non-rare color). When I built it, BrickLink wasn't really what it is today, so it was probably more like $500-$2000 at the time, depending on how lucky you got with your sources.
Anyway, I never actively tried selling my AT-AT, but I got several offers from people who were willing to pay in the $500-$1000 range. So, people were willing to pay approximately what they felt the pieces themselves were worth, but no more.
I know a few other AFOLs who have sold MOCs, but the pre-built MOCs typically don't sell for that much. In my experience, the few other AFOLs I've known to have done this have either regretted selling or simply changed their minds and didn't sell, because it wasn't worth it.
There are a few people out there (Dan Siskind is the only one who comes to mind) who made "kits" of comparable size and were able to sell them at a worthwhile price-point, but from what I know they're few and far between. I believe most of the AFOL-designed kits are smaller and sell for a more "affordable" cost, like $100 or less. Of course, those also come with instructions, and are easy to ship, unlike this where you've got to figure out some way to send a completed (and likely delicate) model through the mail.
Anyway, I'd expect you'd make about the cost of pieces, but not really any more. So if you need the money, by all means go for it, but I wouldn't expect it to really sell for all that much. I'd doubt you'd meet the $900 reserve on eBay.