A set number of enlargements, depending upon the details of your photo package, from budget to a platinum package
Printing uses physical processes and tools to transform a digital image into a top-quality hi-definition print image, so you're mostly paying for the actual process of creating prints, and the same applies to enlargements that take specialty sizes of paper stock on which to print the images.
Prints cost a nominal amount per small sizes, such as $.15 for a 4x6, $.99 for a 5x7, and a big jump to $7.99 for an 11x14, $17.99 for a 16x20, and $22.99 for a 20x30. Since larger printings are not as numerous in demand as 5x7s, the cost is higher, and again, the use of more processing solutions and specialty-size paper also accounts for the jump in price. [These price examples current via Shutterfly at the time of this writing and not guaranteed for your purchasing at any time.]
One item that surprises couples is the traditional wallet-sized photo of the wedding portrait, intended as inserts for the thank-you notes (according to tradition that may or may not be followed today.) According to Shutterfly's current price online, and again not a guarantee for your purchasing at any time, 4 wallet-sized photos cost $1.79. Let's say you need 200 of them; that's about $90 for that one item alone.
And a reminder that anytime you can't wait to receive a wedding item, rush fees will be pricy. Expedited shipping of wedding photos is often noted as something to avoid when on a wedding budget, and it was a particular challenge in the days before online photo posting and smartphones. Decades ago, a wedding couple didn't see one photo from their wedding for months. If a friend brought a camera, maybe it was a week or two before they saw images from their wedding. Now, we've all lost our patience to some degree or other, leading to an 'I can't wait' mindset for print wedding photos ' which leads to pricy rush orders and overnight delivery.