Delta-B PCB panels
Here are some PCB panels that you can use with PCB services like DirtyPCBs - the services that allow panelization will give you the best bang for the buck. If you use something JLCPCB, you can still save money by using the JCLPCB-friendly panelized PCB files - see below.
"Front, back and spacer" panel
"18650, keypad and speaker adapter" panel
"18650, keypad and speaker adapter + mods" panel