Nice 4 post. Pro Park 9 PLUS - Direct Lift if this is one you acquired that's about $3,500 USD. I guess you're looking to double storage real estate.
I'm shopping for a 2 post for ability to work on everything with tires off. Quick search reveals least expensive, a Chinese unit... @$1,709.00 free shipping. I'll keep shopping...
Look at a Max Jax by Danmar, made by Bendpak, I have one, bought 7 years ago, paid $2200.00 CAD. It works great, no complaints, lifts about 4 ft or so, 6000 lbs capacity, unless you have a high ceiling it would work well.