See what's great about restoration jobs is there way, way less overhead. So price what you need to make the job profitable for you and your business.
Here are some things to consider, as I've done mostly restoration work.
How sunken are they? Are you going to need to add more quarry process?
How long ago was this installed originally? There may be a REASON it sunk. Hint: There probably is!
Usually this is because the base that was laid was never deep enough. I usually like it to be at least 8 inches for a walkway or patio.
Make sure you pitch it correctly. All the Sakrete in the world isn't going to do it any good if its not pitched.
Always ditch whatever edging is already there. I've never used landscape fabric, but I know some people like to use it.
If you need to dig it out again, it's going to take a lot longer than 10 hours.