My guess is their not interested in the small fry and are looking for companies that earn hundreds of millions.

If a company was gaming this pricing creating 100 products each earning $4,000 (vs. $400k) they are saving $15,000 and are likely to hurt their business via customer confusion.

That does not scale really well, unless are really on the edge of this 3k. As soon as you start earning more, your users will be confused if you release 'new' product every month. Besides, I bet if you read full license, it will have proper legal rules there against this and other tricks you might come up with.

I think maybe this falls under the EULA?

"6. Records and Audits

You agree to keep accurate books and records related to your development, manufacture, Distribution, and sale of Products and related revenue. Epic may conduct reasonable audits of those books and records. Audits will be conducted during business hours on reasonable prior notice to you. Epic will bear the costs of audits unless the results show a shortfall in payments in excess of 5% during the period audited, in which case you will be responsible for the cost of the audit."

Yeah, but I think $3,000 is a small enough increment for them. You'd need to do this dozens of times for it to be a meaningful aggregate amount. And that situation should be fairly obvious and easy to police.