Strictly speaking raising the price isn't necessary to limit order volume; you could just ... limit order volume. There are X widgets available in 2018, and on

Strictly speaking raising the price isn't necessary to limit order volume; you could just ... limit order volume. There are X widgets available in 2018, and once they're ordered, they're gone. Granted, raising the price may also be good, because it restricts the market to "people who are willing to pay more" rather than "people who happen to order first", but sometimes that isn't desirable (this is a constant argument around eg PAX tickets).