Really? He gain 9k at months and his computer create only 500 renders? Are u serious?
I'm not a big fan of L&P but reading such bullshit shows that you don't know much about the work which goes into creating a VN.
Your statement that a high-end computer (hardware) can produce more than 500 renders is correct, but creating 500 renders isn't simple pressing the "print" key on your keyboard. Setting up a scene takes time. Model pose, lightning, props in the background, texture of clothes and models etc, and don't forget that each render needs to undergo postwork via Photoshop as well.
The actual render time doesn't take much time - maybe 1/3 of it. 2/3 is spend on above steps.
So yes, a better rig can produce more output but a single dev can't increase his output without additional help (workforce). Hiring a second artist to double the amount of renders isn't working either, because each artist has their own unique "handwriting".