That is a beautiful, classic edition of The Book of Common Prayer.

Based on the images you provided, here is the information regarding its publication year and a general overview of its value:

 Publication Year

The publication date is clearly indicated in Roman numerals on the title page:

• M.DCCC.LX translates to 1860.

• M = 1000

• DCCC = 800

• LX = 60

The book was published by D. Appleton & Company in New-York.

There is also an interesting certificate inside, signed by Benjamin Dorr, President of the Standing Committee of the Diocese of Pennsylvania, dated Philadelphia, June 7, 1845. This date refers to the Standard Edition of the prayer book text that this specific edition was compared and corrected against, confirming it is a printing of the 1845 standard text.

Potential Value Overview

The value of an antique book like this depends on several factors, including condition, rarity, and binding, but here is what the search results suggest for a Book of Common Prayer from D. Appleton & Company around 1860:

• General Value Range: Similar copies of The Book of Common Prayer from D. Appleton & Company published around 1860 (including a few years before and after) are often listed for sale in the range of $50 to $150 USD online.

• Binding: Your book has a distinctive, decorated leather (or similar material) binding with a cross design, which is attractive to collectors. A unique or high-quality binding can increase the price.