The reason they've sold fewer FAS2000 Series...
These models don't support DataONTAP 8 or later, since the CPU's in the current line are not 64bit.
This means that they won't be upgradable to the current release of ONTAP without swapping the storage head for a new model. These devices are effectively obsolete at point of sale.
Consequently if you want to ensure your system has a good software upgrade path, and you were wise enough to ask about it, you were up-sold to a 3000 series that has 64bit processors. Everyone else is looking at a head swap at some point.
The FAS2240 is the first 2000 series that has a 64bit CPU and is able to take advantage of the larger 64bit aggregate sizes and the new features in ONTAP 8. Seems very odd that NetApp have had ONTAP 8 as general availability for ages now, yet not all of their current models support it. Sort it out NetApp.