The correct towbar is extremely important. Fit the wrong towbar to a car and the caravan may not stay in place. The capabilities of a towbar are often over estimated. Generally the only part that is visible is the tongue or lug. Sometimes this appears to be quite strong. However the actual mountings or strength of that part of the bar that is under the vehicle may leave much to be desired.
In relation to towbars, there should be no comparison. Sure the cost may be a little more than you had budgeted for, but compared to the investment you have in the towing vehicle and caravan, it is cheap insurance. Always purchase a recognised product from a tow bar specialist. A plate, which displays the manufacturer's name, the vehicle for which it is designed and the bar's maximum towing load can identify a quality tow bar.
If you purchase a new vehicle with a towbar already fitted, do not assume that it matches the towing capabilities of the vehicle. Many towbars are only designed to tow small trailers and not heavily loaded caravans. Before selecting a towbar, firstly determine the loaded weight of the caravan or camper trailer. This can only be done by placing the unit on a weighbridge. Then purchase a towbar that can adequately cope with the load you intend to pull.