My DR-1000 was about $75 shipped --- pure luck, from somebody that did not know what they had, misspelled it on eBay (and had an awful description), years before videoheads were really talking about these devices online like we do now. I got this back in 2004.
It's not likely to happen again.
The units are about $300 new, maybe you'll get one for $150-200 if you're lucky. These are low-production items, bought and sold by knowledgeable users, and tend to hold most of their value for that reason -- sort of like AVT-8710 TBCs or TBC-1000's.