You can also go on Amazon and search for the Starter Kit...but it will likely be from Arduino SRL, a unethical and criminal enterprise in Italy who you really don't want to support intentionally.
Unfortunately, this is the only way to get the 'Starter Kit' atm AFAIK and how I got mine.
However, having had a look at the components of the 'Basic Kit', on first hand, it appears that it contains the same components and exercises but not the large book (instead giving access to exercises on Project Ignite/Autodesk) so it probably is a like for like replacement for the previous Starter Kit.
Have a look for yourself..
Starter Kit:
https://www.arduino.cc/en/Main/ArduinoStarterKitBasic Kit:
https://www.arduino.cc/en/Main/ArduinoBasicKit