Ultra Lite vs Normal Weight

From what I have seen, they are built cheaper to get lighter. Tires, axles and brakes are cheaper, cheaper frame, etc. Push on the walls and floors and see how it gives. Cabinets are plastic laminate over particle board, cabinets are stapled rather than screwed and glued.

Quite right, Ultra Lite = Flimsy and Cheap. And will fall apart in a year or two.

As for aluminum, Arctic Foxes are all aluminum construction and are some of the heaviest campers you can buy. I doubt these ultralight units have much aluminum, for one thing that costs more.

If you only intend to use the camper for a couple weeks a year and you carefully cover and care for it, then maybe it makes some sense to go cheap. With the understanding that the camper may not last as long as the loan to pay for it does.