Just wanted to add my $0.02. The brand of lift is a significant factor in how easy the columns are to stand up and move around. The Atlas, Bendpak, Rotary, for lifts under 16,000lbs all of which are made in China. These lifts are quite light and can be lifted upright by two people. I payed about 3X the price and bought a US made Mohawk 10,000lb lift. I won't debate the US vs China here other than to say I wouldn't recommend the Mohawk to everyone as the value proposition isn't always there.
I had to use the forks on my front end loader to lift one end and stand the columns upright on the Mohawk. Each column without arms weighed in excess of 1,000lbs. That means the top end that I had to lift to stand the column up weighed just less than 500lbs, which the 2 people I had on hand couldn't lift off the floor.
Moral of the story is to get the weight info from the manufacturer to determine how much each column weighs. Remember that the older lifts that were made in the US are significantly heavier, so if you are installing a used lift, keep that in mind.