Listing fees for AWS Marketplace are marginal compared to the overall margins of Enterprise SaaS, as 90% are the expected target margins in Enterprise SaaS - hence why 80% discounts are fairly common in enterprise sales.

More tactically, excessive charging on marketplace pushes vendors away from selling on AWS Marketplace and makes them develop alternative deployment methods, which reduce the stickiness of AWS, as hyperscalers are commodified nowadays.

Motorola learned that the hard way 40 years ago when pushing excessively restrictive OEM and Partnership rules compared to IBM.

AWS is only as strong as it's Partnership ecosystem, as companies that are purchasing tend to use 80-90 different apps along with their cloud.

Basically, Enteprise Sales shows hallmarks of a Stag Hunt Game, so a mutually beneficial pricing strategy amongst vendors (AWS, AWS Partners such as Nvidia, MSP) is ideal.