I don't want to get into exact prices because this thread isn't about the money but you're looking at about $15-17K to get the truck through a US port. You'll need at least a few grand in the bank in case something goes wrong.
In the end, you'll end up with a MOD 110 and it's important to set your expectations properly. You may luck out and get a nice truck like this one but you're definitely not getting the typical consumer-focused Defender. There are many funky military-specific things; for example, the truck has military-style light switches which may be confusing to the unexperienced at first. My truck is an FFR ("Fitted For Radio") truck, meaning that it has a massive (in size) 90A 24V secondary alternator, along with a big battery cabinet in the back. I'm going to remove the cabinet because it chews up much of the rear tub and I'm never going to fit military radios to this truck. On the plus side, it has the two side lockers that hold two NATO fuel cans each. The truck has a nice Defender dash but it came without a lot of the interior trim that the civilian trucks have. There's no dome light and there are no door cars to hold speakers. It's a very spartan setup and perfect for what I do.