Tesla could create a 1-megawatt hour version of the Cybertruck that would have 3500 miles of range and have JLTV level armor. The Cybertruck weighs 5000 to 6500 pounds and 14000 pounds of payload capacity. The JLTV (Joint Light Tactical Vehicle) weighs 10,000 pounds. Extra weight would for the megacybertruck would be used for extra armor and batteries.
Tesla's new batteries are now at $80 per kwh. The energy density of the batteries is about 300 watt-hours per kilogram and will be improving to 500 watt-hours per kilogram. Around 2022, Tesla batteries would be about 400 watt-hours per kilogram. 1 million watt-hours would be five times the premium tri-motor version battery pack. It would only weigh 2,500 kilograms (5511 pounds). These batteries would cost $160,000.
The JLTV costs about $500,000 each. You could spend $75,000 on the premium tri-motor Cybertruck and upgrade with $130,000 worth of extra batteries. It already has $30,000 worth of batteries. Add in $100,000 or so worth of armor for a total cost of $300,000.
The range and the reliability of a Tesla megacybertruck would totally outclass the JLTV. Cybertruck will have the 1 million duration batteries. There are far fewer parts for electric engines.