If you are buying watches to make money, then I will bet you wont. Its a very difficult thing to wake up one day and decide to make money trading in something that others have been doing for years.
Except in a rising market, when everyone thinks that they can make money buying any old watch. And in a rising market they do. Its like the school sports day where everyone gets a prize, "For taking part". Well everyone feels great for a while before wondering why in the real world they cant win anything.
When the market stabilizes then most hobby dealers lack the skills, or ability, to add value to trade successfully. Some have zero trading morals and that doesn't help them, while it can be overlooked when everyone is scrabbling to get on the bandwagon.
So then they panic, and we see all their lower quality watches coming on to the market, at too high a price, and then the perception is that the market is falling. Its not, its just a whole load of watches that were bought to make money on, rather than because they sang to the buyer.
This has happened with 105.003's recently. A whole load of them have appeared on the market and remain unsold under $15,000. And yet I still see special ones sell for well over $20,000 if they are attractive and correct.
Look at this and you will see what I mean on Chrono24. 38 watches for sale at time of this post, not one NOT ONE is attractive let alone worth the money.
I challenge anyone to find one worth buying in those 38 watches, or one they would recommend to a friend.
So my real answer to the OP is:
If you have to ask....then you probably should not be doing it.