This appears to be a high-tech post-apocalyptic world.
Perhaps they do have MedKit™ technology that can restore your family to full hitpoints. But you're not a medical technician. You don't know if they do, or how to use it if they do have it. And if you wind up using it wrong somehow, the hometime doctors won't have any experience dealing with what you may have done to them.
You have a reasonable idea how to use gold.