Mark Simonson has an interesting and fun memoir of his days using the Atari 8-bit line for entertainment and work. He discusses graphics modes, the pain of publishing color digital art without a printer, and the advent of the Macintosh.
This jumped out at me:
free upgrade to a new graphics chip—the GTIA
It seems Atari shipped with undersped chips and replaced them under warranty:
The original design of the CTIA chip also included three additional color interpretations of the normal graphics modes. … This feature was ready before the computers’ November 1979 debut, but was delayed so much in the development cycle that Atari had already ordered a batch of about 100,000 CTIA chips with the graphics modes missing. … the company decided to use them in the initial release of the Atari 400 and 800 models in the US market. … Atari authorized service centers would install a GTIA chip in CTIA-equipped computers free of charge if the computer was under warranty; otherwise the replacement would cost $62.52.