Sure, it's easy to evaluate anything if you make up plausible-sounding numbers about it.
The costs of printing and retail are definitely less than half the sales price: https://www.davidderrico.com/cost-breakdowns-e-books-vs-prin... Publishers say it's 10%; Derrico thinks they are underestimating certain logistical costs but no way it's 50%.
Did you read that? You’re picking out one cost: printing.
Scroll down to where the cost breakdown of a paperback is. More than $5 once you include distribution and retailing.
Or, as some might say, more than 50% of $10.