You are comparing a Mercedes to a Yugo. The Yugo is definitely cheaper, and WILL get you to the grocery store.
Your description of the $200 tow bar doing "just as well" is very, very subjective.
The Ready Brute is MUCH easier to hook up. You can be off a little on your alignment or distance from the MH, and still hook up.
The Ready Brute is MUCH easier to unhook. Even when the tow bars are in a bind because the car is not DIRECTLY behind the MH, you can easily unlock them, pull the car forward 1 or 2 inches, and relieve the pressure. Neither of those are possible with the rigid tow bar.