The price is always set by the user in #v4v. They're the only ones that know how much value they got out of your product and how that translates into a monetary value. Sometimes that's only 100 sats and sometimes it's 1,000,000 sats. Once you start suggesting prices, you're essentially putting a maximum price on your product. You're telling them that your product is only worth a certain price when it might be worth a lot more to the user. Similarly, users who can't afford your suggested price or don't want to pay it will pay you zero rather than something.