An underrated John Carmack factoid is how he leveraged ultra-premium workstations (several years ahead of the rest of the market) in order to create the Doom & Quake series[1]. In 1991, before embarking to work on his early FPS game titles, John Carmack spent $11,000 ($23,219.85 inflation-adjusted) on a NeXT workstation. The story of his purchase is chronicled in Masters of Doom:
> On a cold winter day, Carmack laced up his shoes, slipped on his jacket, and headed out into the Madison snow. The town was blanketed in the stuff, cars caked in frost, trees dangling ice. Carmack endured the chill because he had no car; he'd sold the MGB long before. It was easy enough for him to shut out the weather, just like he could, when necessary, shut Tom and Romero's antics out of his mind. He was on a mission.
> Carmack stepped into the local bank and requested a cashier's check for $11,000 [$23,219.85 inflation-adjusted]. The money was for a NeXT computer, the latest machine from Steve Jobs, cocreator of Apple. The NeXT, a stealth black cube, surpassed the promise of Jobs's earlier machines by incorporating NeXTSTEP, a powerful system tailor-made for custom software development. The market for PCs and games was exploding, and this was the perfect tool to create more dynamic titles for the increasingly viable gaming platform. It was the ultimate Christmas present for the ultimate in young graphics programmers, Carmack. – Masters of Doom, pg. 93
Carmack also shelled out $10K to use the world's first 1080p monitor, which he used to create Quake I, Quake II, & Quake III:
> [In] 1995, Carmack spent $9,995 on one the first 1080p monitors: the Intergraph Interview 28hd96. This monitor was gigantic, but the extra screen space and image quality surely came in handy during the creation of the Quake trilogy. It provided a 28" screen with 1920x1080 @ 85Hz, a resolution not unheard of on today's hardware. Essentially, Carmack was able to trade $9,995 of 1995 money for a monitor that put him decades into the future.
> On a cold winter day, Carmack laced up his shoes, slipped on his jacket, and headed out into the Madison snow. The town was blanketed in the stuff, cars caked in frost, trees dangling ice. Carmack endured the chill because he had no car; he'd sold the MGB long before. It was easy enough for him to shut out the weather, just like he could, when necessary, shut Tom and Romero's antics out of his mind. He was on a mission.
> Carmack stepped into the local bank and requested a cashier's check for $11,000 [$23,219.85 inflation-adjusted]. The money was for a NeXT computer, the latest machine from Steve Jobs, cocreator of Apple. The NeXT, a stealth black cube, surpassed the promise of Jobs's earlier machines by incorporating NeXTSTEP, a powerful system tailor-made for custom software development. The market for PCs and games was exploding, and this was the perfect tool to create more dynamic titles for the increasingly viable gaming platform. It was the ultimate Christmas present for the ultimate in young graphics programmers, Carmack. – Masters of Doom, pg. 93
Carmack also shelled out $10K to use the world's first 1080p monitor, which he used to create Quake I, Quake II, & Quake III:
> [In] 1995, Carmack spent $9,995 on one the first 1080p monitors: the Intergraph Interview 28hd96. This monitor was gigantic, but the extra screen space and image quality surely came in handy during the creation of the Quake trilogy. It provided a 28" screen with 1920x1080 @ 85Hz, a resolution not unheard of on today's hardware. Essentially, Carmack was able to trade $9,995 of 1995 money for a monitor that put him decades into the future.
[1] https://simulavr.com/blog/paying-for-productivity/