If you are going to build a simple, plain jane bar or cage that looks like one of the kits they sell and has few bends, then a manual machine will work - after you clear an area in the shop, drill holes in your floor, get the thing mounted and then unbolt it when you are done and throw it in the corner so you can use the space. But if you are going to do more than one, do it to make money, want to do something custom that fits the car nice and doesn't look like a kit and don't have people hanging around to help support the material in the machine and pull the lever around, spend the money.

I have an electric over hydraulic system with a controllable valve on mine that can be used to run the ram very slow to creep up on an angle on something where the fit is critical or run it wide open and pull a 90 in large diameter 4130 in a matter of seconds. It's worth WAY more to me than it cost.