Why does a Nuvi 780 sell for more than a 760?


Has anyone noticed that the cost of the MSN GDB-50 power cable ($119.99) costs less than the FM Traffic GTM-20 power cable ($214.27). You can buy a Nuvi 760 for around $400 with the more expensive traffic cable & the Nuvi 780 sells for about $570 with the cheeper MSN cable. You could buy a Nuvi 760 & the MSN cable for less money than if you bought just the 780 & have 2 traffic cables, one with a 1 year subscription rather than a 3 month trial. Does anyone want to trade or sell their MSN cable as I live in a area that only has MSN coverage. I own 2 Nuvi 760s with unused 3 month trial subscriptions.