I buy a lot of systems on Yahoo Auctions Japan and get them refurbished/recapped and have a lot of systems for sale at the moment (mostly briefcase units). I can tell you that it will be over $100 for a complete set up but I think I can get you a good deal so send me a PM in you are interested! I should be posting a thread with more info in the next week, but I've just been really busy!
By the way, the auctions you posted are at low prices now because they aren't finished yet. Most of the bidding on these kind of things happen in the last couple hours. Generally working DUO-R systems go for 7,000-9,000 yen depending on the condition/accessories, which is over $100, plus airmail shipping will cost at least $70 or so. Add a proxy service and you're looking about $200. The other two auctions will definitely get bid on as well. I usually buy systems with problems and get them repaired. Sometimes it's impossible and I end up with dud systems but a lot of time a repaired/recapped system will be a lot more reliable than one that has never been worked on.