The Daytona in steel (black or white dial, does not matter) is quite hard to come across, depending on where you're looking at though. The basic reason for this is that Rolex, who make around 800,000-900,000 watches per year, make the SS Daytona in much fewer numbers compared to their other models or evenly compared to all other Daytona versions.
For example, it is not so hard to get one in the U.S. There are dealers and wholesalers there who can get you either (black or white dial) in a week or so. It does not happen everywhere but generally speaking this is the rule across the pond.
If on the other hand you look Eastwards, e.g. Europe or Asia, the picture is quite different. For example, the Daytona is an object that enjoys cult status in Japan. There is even a magazine only for the Daytona there (from what I have heard). SS Daytonas sell rapidly fast and at full list price in Japan.
In Korea and China it is not so easy for a dealer to receive a SS Daytona, same applies fro Europe - these dealers have to fight for it. The situation gets even worse for Duty Free Shops. Last year I went through Singapore's Changi airport and the Rolex boutique in T3 had both in stock (which is very uncommon).
I bought mine (a two-tone 116523) a year ago for around $13,500 at a duty free shop in South Korea. Beauty is in the eye of the beholder, and you should choose what you like (aesthetically). Any contemporary Daytona is the same, they carry the same movement. Yes, it will be much easier to sell a SS one as these are the cheapest in the range and quite rare, but if you are buying a watch only to sell it some months or years later then what it the purpose. So all the discussion about rarity etc. is not necessarily relevant. However it is true that the SS Daytona or any gold-cased one (strapped or with bracelet) are generally much more preferable by Rolex fans worldwide.
In general, the Rolex models which are hard to come by are the SS Daytona, the thick and very heavy Sea Dweller Deep Sea (dealers usually get one or two of these [SDDS] every year, if they are lucky) and lately we have the newer Submariner with "no date". You may have seen a picture of S. Theron wearing the SDDS while attending an NBA game. On the other hand, the Sub is admittedly quite the most iconic Rolex model, together perhaps with the two-tone Datejust on a Jubilee bracelet. However, when one wears a Daytona on her/his wrist, they immediately discover how easily and enjoyably it wears (at least from the Rolex range).
The Daytona may have no-date, but it is very elegant, classy and at the same time sporty. It is sleek and wears very discreetly. The 40mm size is quite ideal for most wrists, and generally at the end of the 'range' where a reasonably-sized watch should at least be. There is a reason why most classic watch makers used to make their timepieces (and still do) with an average size of 36mm for either men or women.
I have heard of 7-year waiting lists in Japan for SS Daytonas, and lately for 3 to 5-yr waiting lists for the same model in Germany. But if you get the chance to travel you may easily find a nice bargain at a duty free shop (e.g. Singapore). Another good source is trusted sellers in a reputable watch forum.
I'll close with this: I have a friend here, avid watch collector, who once told me "...If/when you find a new SS Daytona, buy it blindly; if you find two, buy both..." Personally I still have to get a SS one, may be one day when I sell my SDDS or vintage GMT II, but it is true that the SS version of this iconic model is quite hard to get and retains highest value after purchase.