The Canon EOS 5Ds and 5Ds R are both in stock at the top rated plus USA seller Get It Digital.
Canon EOS 5Ds R Body – $3,799.99 – at Get It Digital via eBay
Canon EOS 5Ds Body – $3,429.99 – at Get It Digital via eBay
FREE In-store pickup – Buy on eBay and pick up at your local Get It Digital.
Note: These are imported models. You will get 1-year USA warranty from Get It Digital.
GetItDigital is a reliable unauthorized dealer and has excellent eBay feedback. It has been historically honored by Canon USA at their discretion. There are no physical difference between imported models and USA models.
If you are comfortable with imported camera gear with a seller warranty, that will be a great deal for you.
The 5Ds is in stock at most online stores, while 5Ds R currently is out of stock almost everywhere.