Think again. The Low Res Prius updates are $200.
But there is hope.
There were enough issues with the original Prius map database they issued one free update via a recall.
I have noticed the routing is poor if you are out of one of the "Detail Information" areas. It shows secondary roads but won't route using them even if your destination is on a secondary (not a dirt road either) road. I think we are giving up a lot with the Hi-Res. I know my '04 Prius did a better job in outlying areas.
J