Are there any major digital stores that disclose the costs of doing business (royalties, fees, etc...) to the customer as purchase? For example, the PlayStation/Xbox Online Store or Amazon Music
In the US, sales tax is almost never included in the price tag, so, when you checkout, you get the sales tax itemised separately, including when different jurisdictions charge separate taxes (e.g., county + city sales tax). Hotels in states with a gross-receipts tax often pass this tax back to the consumer as well.
In Eventbrite and many other similar apps, including for donations, the processing fees are nearly always shown separately from the cash price itself; I believe some platforms let the seller decide how it's shown (e.g., "who pays it").