To be honest, buying watch is not for investment but enjoyment, the thrill of a watch chase, a sense of achievement and the envy of others.
If you wear your watch for 2 years and still can break even,this is good enough le.
It you want investment do it the proper way, blue chips, bit-coins, FX or other established trading platform.
The other spectrum of watch collecting is watch flipping, this my friend is not collecting nor enjoying but 100% into making quick profits. (Your purchases purely depends on trends and demands, you might not like the watch at all but you are buying for the sake of profiting)
So ultimately which side are you on?