Adjustable frame beds all share some basic features. They are built on a strong and stable metal frame. This frame is made of steel. Therefore, it is quite heavy. Good adjustable beds use heavy duty steel. Less expensive beds apply lighter grades of steel. They are less durable than the heavier metal versions.
The long sides of the adjustable bed are rails on which the movable parts of the bed are sliding. The outer sides of the bed frame are covered with softer materials, veneers or laminates, to make them look more like the outside of a spring mattress.
This metal frame needs to support the weight of the sleeper(s), the weight of the mattress and the heavy equipment that is attached underneath the bed frame. One or two electromotors are the heaviest parts.
The support for the mattress and the person using the bed normally comes from a slatted surface or strong plywood. Modern adjustable beds use other man-made materials as a flexible base. Slatted base designs are lighter than the full mattress base. They require less powerful electric motors to move the base parts into the desired positions. On the other hand, stronger full mattress bases require two or three stronger motors for the same function.
When considering an adjustable bed, these factors are most important. The stronger the bed frame and the mattress base, the more weight it can sustain and the longer it will last under daily use. We also have to keep in mind that basically all mechanical functions of the adjustable bed are supported by the metal frame and the mattress base.
A better frame and more electric support features come at a price; in weight and in money for the purchase of the adjustable bed. Cheaper beds most likely have somewhat cheaper construction materials. But they are lighter and cost less to ship. Heavier adjustable beds cost more and, most likely, last longer under stress.