"Regardless of whether support is purchased, then, organizations
using Ubuntu servers get free access to security fixes and other
updates that Canonical endorses. But Ubuntu only makes economic
sense if a good proportion of its servers in a given organization
are unsupported. That's because the support contracts (which
include limited indemnity against claims of intellectual property
infringements from the use of Ubuntu) that Canonical offers are
more expensive than those offered by Red Hat: Canonical charges
$2,750 per year for 24X7 support, while Red Hat's subscription is
$1,299 for servers with up to two sockets or $2,499 for more
powerful machines, and Novell's subscription is $1,499."