BuyDig is showing that the Canon EOS-1D X Mark III is in-stock for $6499.00 — this includes the free 64GB CFexpress card and reader (the pre-order bonuses).
BuyDig is an authorized Canon USA dealer, so this item carries a 1-year Canon USA warranty. As most other dealers appear to be out-of-stock at this time, there is likely very limited quantity available at BuyDig.