So, we primarily award points for replacement parts priced at 25% of MSRP or less (exclusive of tax and shipping, because those vary regionally).

As a historical aside, although we’ve had our eye on this for a while, we only formally added replacement parts to the iFixit scorecard fairly recently—it’s factored in for many (but not all) of the devices we scored during the past year. We’re updating how repairability scores are displayed to help make that distinction clear.

https://www.ifixit.com/News/75533/how-ifixit-scores-repairability