OK, so a lot of things to consider!
First, in regard to the gold watch vs. the steel version of ANY BRAND.
For some reason, while gold watches command a MAJOR premium in the retail marketplace, they are really difficult to sell in the secondary market, and often sell for FAR less than the original price.
Even on brands like Rolex and Panerai, which consistently hold their value, gold Rolex's and Panerai's DO NOT.
A $30,000 gold panerai will sell for $16,500 used. Almost a 50% drop! Whereas the same watch in stainless will sell for about 20-30% less than retail.
So I would NEVER, and this is just me, buy a gold watch NEW. ALWAYS buy used, and take the time and energy to authenticate!
The Daytona, in stainless, is still not only one of the more difficult watches to obtain, but manages to hold its value intensely!
So, if value retention is key to you, STAY AWAY FROM GOLD WATCHES.
Now, onto the online vs. retail avenue.
Anyone who has a Daytona in stainless will likely demand full retail or more, as they are difficult to come by.
You MAY be able to swing 10%...
Two-tone Daytona's are NOT hard to come by, and you should be able to push about 10-20% off on them, even at an AD, I don't care what anyone tells you.
I would buy a Rolex ONLY at an AD, and here is my logic.
I have seen and held replicas that fool watchmakers. Some of the new stuff out of China has serial numbers, swiss movements that look and function like ROLEX original... they even have the mini holograms. It is NUTS.
Other brands that are not as replicated, it makes sense to buy online and save BIG.
With Rolex, I would go to an AD and wheel and deal!
Good luck, and if you need further info/advice, do not hesitate to ask!
-Wired1