Proofs are standard prints. A standard print is what a mine-photo lab does. The negatives are printed full frame with out any cropping. If the negative was exposed correctly and framed and centered when the shot was made, good quality standard prints can be made for your album. You my even chose to use many of your proofs supplementing them with larger prints in your album.
Professional labs make custom prints by hand.
An experienced color printing professional will center, crop, straighten and color balances each print. They can also lighten and darken parts of the image to enhance the final print. This is why custom prints cost more then standard prints. I can help you in determining which is needed. Like prints, albums are marked up 2-6 times.