I think it is great that you know what you want & have set a goal for yourself to attain your dream watch. Just be sure that this is the watch you really want before you spend all your money. I have been collecting watches for many years & my tastes have changed alot since I was in my 20s. While the Defy is a clever piece of engineering, it is definitely a niche type of watch (meaning that it is like a fad, where it is popular today, but may not be so popular when the styles changes tomorrow), so I am not sure it will retain its value 5, 10 or 20 years into the future.
Still, it sounds like you are well on your way to your goal of $25,000. So keep your eye on the prize & do not let anyone or anything deter you.