my opinion is that one should never buy a watch as an investment. one should buy a watch that the person can associate with (sports, dress, diving, aviator, racing, casual beater etc) and the sentiment it provides when worn on the wrist.
the misconception of watches appreciating within a short span is a myth. like a car, you lose 20-25% once you drive it out of a showroom - similarly, it happens to watches once you walk out the AD. hence, many choose the pre-owned route where one can buy, use, then sell while minimizing difference.
there are many investment tools and facilities out there if you want to make your money grow. positive returns on investments in watches seldom happen around new/modern watches.