IDC notes that the ASP for smartphones as a whole has been boosted by the rise of "phablet" devices, which are generally more expensive as they require more powerful and expensive components. The ASP for phablet devices was $443, notably higher than the overall average.
In the longer term trends Apple has maintained the highest ASP in the industry by some distance, a result of it decision to focus on the higher end of market. While older iPhone models (currently the iPhone 4S) are traditionally available at lower prices, the sales of these devices make up a relatively small proportion of Apple's overall sales.
BlackBerry has seen a rise in its ASP this year, a result of the launch of its more expensive BlackBerry 10 models. Higher cost devices now make up a higher proportion of BlackBerry's overall sales, but this should be set against steeply declining sales unit volumes in the same period.
Android has seen a gradual decline in its ASP over the last 18 months, a result of both an increased sales of low cost devices and a lowering of the entry price point (i.e. low end Android devices have become cheaper and sold in greater numbers).
After a rise in ASP in Q4 2012, a result of the launch of Windows Phone 8 devices, Windows Phone has seen a decline in its ASP in 2013. As noted above, this is the result of an increase in the proportion of lower cost devices being sold (mainly the Nokia Lumia 520 and 620).