Annoyingly, neither the price nor the spec have been updated recently. The non-developer XPSes are already on Skylake and come with more RAM and storage: http://www.dell.com/uk/p/xps-13-9350-laptop/pd
12.04 is still under LTS support by Ubuntu for another 4 years (LTS releases are supported for 7 years), so even if it's "old" it's also receiving active support. That being said, there's nothing stopping you from upgrading to 14.04 yourself.
small correction, Ubuntu supports LTS releases for five years. Support for 12.04 ends in 14 months, in April 2017: https://wiki.ubuntu.com/Releases
Thanks! I swore it was 7, but you're completely right.