That's still what $7500-$10K per Telsa though isn't it?
But that's a huge part of the car, and the majority of the drivetrain cost. The motor costs probably a few hundred. When you consider all the things it actually replaces -fuel and exhaust, starter and alternator, a number of ancillaries- it's really starting to close in on an internal combustion engine. Not to mention that that level of drivetrain is high end in terms of power output.
The battery has represented ~80% of an electric powertrain's cost, so it's a reasonable proxy for replacing most of the powertrain. Even parts that aren't fully replaced, like the heater core, A/C and radiator are made significantly cheaper. It's very much an estimate, but it isn't inaccurate.
Recently it's becoming less representative. Drive stages (electronics) are getting more exotic and expensive as manufacturers recognize the value in them, and motors are probably going to continue using limited amounts of neodymium magnets. And of course, batteries have become far cheaper. Personally I can't wait- I want more focus to be on the motors and drivers, which are way more accessible from an aftermarket perspective. It takes tens or hundreds of millions to get into battery manufacturing, but only a few hundred thousand to get into making world-class motors or electronics. Crate engines for EVs are just waiting on the demand (and a friendly nod from manufacturers).