I thought the same thing, and bought the Airlift 1000 kit instead. Tried to go the cheap route. Worked well for one summer and most of one winter. Used them a few times to haul dirt for the our raised garden, worked well at keeping the truck level.
Went to check the air pressure one day shortly before the Spring, and passenger side wouldn't hold air. Tested the air line/valve, and it held pressure. Air bag wouldn't hold it. Tried to take advantage of the warranty, and wasn't terribly impressed. It took three or so business days for them to reply to my first email. After repeating my problem to them again and repeating the my product again and a few other annoying questions, all in separate emails, all of which they could have answered themselves by looking at my warranty registration, they asked me to call them. What was the point of the all the back and forth if I have to call anyway?
So I said screw it, threw them in the trash, and did what I should have done the first time... ordered the Timber Groves.