The mark on the bottom is the production mark, and tells you when the item was produced. Here is a website that has the Precious Moments production marks:
http://www.atticshoppe.com/figurines...ts-marking.htm
The eyeglasses mean that it was produced in 1998
Some of the items might look the same, but come from different years production lines...so might be worth more/less. I have a nativity set that is from the original production (and worth quite a bit), but there are others that look just like it that are worth much less because of the different production mark. They were made after mine.