Well, for an extra $3949.95, you could get this handsome volume 1 of the original printing of the Douay Old Testament:http://www.ebay.com/itm/400267933157
(OK, so your Amazon gift card wouldn't be any good on eBay, but still, for $4000, how can you go wrong? :wink:)
Seriously, though, if I had that much money lying around, I imagine I'd snap that up in a heartbeat! (Actually, I'd try and beat the seller down a little bit first.)
Back to your original question, though. Sadly, there really aren't that many good options when it comes to buying a new Douay-Rheims. What we really need, I think, is for someone like Oxford University Press to publish a proper study version of the Douay-Rheims, with all of the features that you mentioned and at a reasonable price (although I can't see OUP or any modern publisher willing to do that, at least not without adding a heavy dose of modernism to it first).
As others have said, the Haydock really is the best version of the Douay available today. It would just be nice if there were something more compact and portable along the same lines.