What I got from reading all the posts is that the maximum amount it could possibly be is $600 per year--but there has been no official word yet, only speculation. I've also heard $200 and free during the warranty period. However, Tesla has said that they are going to frequently have software upgrades similar to an iPhone, so someone has to pay the programmers. But $600 is a bit much. The 2004 Prius has cost about $1000 per year for tires and maintenance. However, that includes a bunch of preventive maintenance that I think most people don't bother with such as replacing the transaxle fluid and replacing the water pumps (there are four).