Yes, those are all spec sheet numbers and prices, not real world. Real world load capacity will be hundreds of pounds less as you say. That was to show the advantage of starting with a 3500 van with wide load floor vs a 2500 van or a 3500 with too narrow load floor.
On pricing maybe I should have compared base prices, ProMaster 3500 tall ext $41,145 Sprinter 2500 tall ext $43,505 and Sprinter 3500 tall ext $44825. The PM has 530 cubic feet max capacity and the Sprinter has 547 cubic feet. The Sprinter has 3.2% more space. The PM has 3.1% less space. The PM has less angled walls and door openings. It probably makes little to no difference in cargo handling but it may give the PM an advantage as far as outfitting.
The Transit van in tallest/longest configuration has 487 cubic feet, 8.1% less than PM and 10.9% less than Sprinter. Unfortunately there is still little information available to make further comparisons on their years behind schedule vehicle.
On pricing maybe I should have compared base prices, ProMaster 3500 tall ext $41,145 Sprinter 2500 tall ext $43,505 and Sprinter 3500 tall ext $44825. The PM has 530 cubic feet max capacity and the Sprinter has 547 cubic feet. The Sprinter has 3.2% more space. The PM has 3.1% less space. The PM has less angled walls and door openings. It probably makes little to no difference in cargo handling but it may give the PM an advantage as far as outfitting.
The Transit van in tallest/longest configuration has 487 cubic feet, 8.1% less than PM and 10.9% less than Sprinter. Unfortunately there is still little information available to make further comparisons on their years behind schedule vehicle.