Got this to keep our hyper 17lb chihuahua mix away from our senior cats. It's very easily and quickly moved, and the cat door at the bottom works great as well. It *can* be stepped over, but not super easily (ours is the 24") If you want something you can step over, I'd recommend the 18" We'll be getting one  as well when it's back in stock. 

I've seen this sold for 50-$70 in person, so this is about the best deal you'll get.