Religious antique slide locket

I found this slide locket in some broken jewelry that I had bought from a yard sale. I feel like it's worth something because when I look it up online, items like this one are selling between 70-1,000 each. That's why I'm contacting you.

 

On the front of the locket is a vine like image with leaves that almost firm a crown. On the back of the locket is engraved " pray for me" and next to those words looks to be a small church with a cross ontop of it. When you first slude open the locket, you see the religious Madonna( the catholic version of Mother Mary and she's holding a child in her lap. The other image slot is empty, so I assume it's for another picture or to place a prayer in there? 

 

I am wanting to know how old this item is, if it's worth anything and what the image is called that's inside the locket?

 

My name is Tiffany Farren

 

My phone number is 9706201583

 

My email address is [email protected]

I would greatly appriciate if I was chosen. I am really wanting to know more about this item. Thank You and have a Blessed Day!!