Members of Sam's Club can pre-order the iPad Pro in 32gb or 128gb Wi-Fi variants, but it does not look like the Wi-Fi + Cellular model is for sale. Sam's Club is also selling the iPad Pro at a slight discount, offering the device for $787 ($799 at Apple) for the 32GB model and $937 ($949 at Apple) for the 128GB model.
Interestingly enough, the November 13 release date that is cited in Sam's Club pre-order is different than the November 11 date that was previously reported. November 13 does make sense since Apple typically releases products on Fridays and November 11 is a holiday (Veteran's Day) in the United States.
The iPad Pro starts at $799 for the 32GB Wi-Fi edition and jumps to $1079 for the Wi-Fi + Cellular 128GB model. You can learn more about the device here. Apple will also release the Apple Pencil ($99) and Smart Keyboard ($169) alongside the new device.