A smart home lighting starter kit with a hub and bulbs is meant to last for years, automating your routines and saving energy once you set it up. Buying the right kit the first time means you avoid replacing cheap bulbs that drop offline or hubs that stop getting software updates.
Wait for Prime Day or Cyber Monday to buy, since that is when you will see the deepest discounts on smart home gear. If a new version drops right before those sales, look at last year's model instead because it usually gets heavily discounted while offering nearly identical performance.
That intro window is a hard deadline, not free money, so any remaining balance after 15 months will get hit with regular interest.