Breitling and Bentley have always cooperated, but it is not known whether there is such a model. If your friend really owns a Bentley, then the authenticity of this watch is high. Bentley did buy a car to give watches, but that was a few years ago, and now it is rarely given. The design of the outermost circle of the dial of this watch (that is, the dense protrusions) is the same as the gear handle of the Bentley GT, which is the most obvious difference between the Breitling ordinary model and the Bentley model. In addition, the dial says to Bentley, which is also the correct position. I suggest you go to Breitling Store. Some stores will sell Bentley watches. If it is true, it is generally between 500,000 and150,000, because Bentley and Breitling have cooperated in several watches, and I don't know which car your watch corresponds to.
Another way is to look at the back of the watch to see if there is a Bentley model, such as Continal GT, which means that this watch corresponds to Bentley Continal GT, and so on. The more expensive the car, the more expensive the watch.