Birthday gift plan

My mom's birthday is coming up in August, and I plan on making a lapis lazuli and gold wire tree for her. I've made many small ones, and a few larger ones, but this one would probably be one of the biggest I've made. I found a nice piece of lapis for the base, though I want to find something cheaper if possible (this piece is $70), but if not, this one would do very nicely (flat bottom and top, lots of blue). I also know what wire I want to get (gold-filled, 28 gauge), and finding lapis chip beads would be pretty easy. I just hope she likes it!