Stainless steel sports models are the most collectible. Watch enthusiasts don't generally care about gold/two-tone versions, especially when it's about Rolex.
Just compare the vintage GMT Masters... the 1675's go fast and command much higher price than say, the TT "Root Beer" GMT.
I think this would make an interesting discussion. Maybe gold versions aren't considered as durable, or perhaps WIS think that gold versions are only for posers?
But yeah, two-tone Daytona has never been very desirable among the watch community. Everyone wants the SS version. That's why there is the infamous "waiting list" for them while it's possible to source a TT model straight from the dealer. Rolex has a limited supply for the SS Daytona, so the dealers have a good reason to "blackmail" their customers this way: sell it way over the list price.