My belief is that manufacturers use the same heating elements between europe (240V, but often piped to the cold water line) and North America (120V, but usually piped to the hot water line).
No matter what, North American dishwashers will only be able to draw 1500w, and probably less because they're not always on a dedicated circuit, and have other power needs than just heat. So it's probably not a "cheap diswasher" vs expensive one issue.
No matter what, North American dishwashers will only be able to draw 1500w, and probably less because they're not always on a dedicated circuit, and have other power needs than just heat. So it's probably not a "cheap diswasher" vs expensive one issue.