Note prices of the components for 4 down can be much cheaper except for the base plate. A universal tow bar $150, magnetic stick-on tow lighting conversion kit $27 (no installation), and I got a used but like new Roadmaster brake system for $95 from e-Bay.
Base plates are not rocket science. There are a lot of independent off duty welders capable of making a base plate much cheaper. I welded up my own base plate using the same materials and pattern for a Roadmaster for $50 in steel. Years ago I had a Canadian welding license that was stricter than US standards so I trust myself to do a better job of welding than some factory probably in China.
Ever watch a guy try to line up the toad with the hitch ball? The wife directing the husband (and traffic) onto the hitch? My solution was to weld retractable swing-up wheels on my tow bar. The hood on my toad slopes down far enough so with the tow bar wheels down and the tow bar attached to the car, I can see and aim to drive the tow bar straight onto the hitch ball. Then it takes 2 minutes to raise the tow bar wheels, attach safety chains, and plug in the brakes and lights. Maybe takes a total of 3 minutes to attach the toad to the RV.
Main reason we've kept the 2,700 lb 2001 Chevy Cavalier around for 23 years as a toad. The hood slopes down to a knife point, 77,000 miles with zero repairs, 35 mpg @ 70 mph, and the automatic transmission is towable.
My disconnect time is maybe 2 minutes. I added a latch on the base plate to swing the tow bar up off the
bitch (sorry, typo
) hitch ball and lock it a vertical position on the car. I just unplug the tow brakes and lights, undo the safety chains, raise the tow bar off the hitch ball, lock the tow bar up in the vertical position, and park the car. I just leave the tow bar on the car unless I need to drive it. I added a hole to my baseplate latch so I can use a long bicycle padlock to lock the towbar to the base plate. So it can't be easily stolen. I'm positive it would be safe to drive with the tow bar attached to the car but the police might find some way to write me a citation for that.