You are not comparing equal units in their price ranges.
You are comparing a discontinued close-out sale to a lower level current Helix unit.
The Helix 9 SI GPS is the current version of the discontinued 899ci HD SI Combo.
The Helix 12 CHIRP SI GPS is the current version of the 1199ci HD SI Combo.
The Helix 9, 10, and 12 series have built-in Auto Chart Live mapping software, a much brighter display and faster processor.
They will have a longer updatable lifetime due to the faster processor.