| Different design purposes.
The cheapo light doesn't have an on/off switch, the reflector is basically 160* or so and will scatter light over a very large area, has general purpose light tubes, probably warm white, doesn't have any venting as the lamp area is exposed.
The Perfecto has waterproof on/off switch, a directional reflector to focus light into the tank, has lamp tubes designed for aquariums, and is vented so the unit can sit directly on top of a glass tank lid,
I'm not saying it's completely justified to have such a large price difference, but the specifics, or non-specifics, of each fixture change the costs.
Nothing wrong with getting a less expensive 'shop light' and replacing the tubes; you don't necessarily need a switch, a timer works fine.
Also, look at the volume; Big home improvement stores do much more volume than even the biggest discount aquarium stores. More volume means more production, equals cheaper cost. |