A timed shut off is a handy feature on a dehydrator.
On my basic, low cost dehydrator I use an inexpensive pulg-in-the-wall timer but I am looking to upgrade.
The Excalibur you linked to at $223.99 is rated at 600 watts but does not have a built in timer.
They have a different model (the 3926TB) that does have a timer but it costs more at $253.99 and is less powerful at 440 watts.
The one I have my eye on is the LEM Products 10 Tray Food Dehydrator with Digital Timer at Amazon for $199.99.
It is also more powerful at 900 watts than either of the Excaliburs.
http://www.amazon.com/LEM-Products-Dehydrator-Digital-Timer/dp/B004VLKT3W/ref=cm_cr_pr_pb_t