Given the quote for your box, no, in your instance, if it is not needed, you don’t need to spend the extra 0.42 cents. However, just check that whatever packaging you use instead, it will definitely protect the bulb and light.
There are other ways to add color to your main image. You can create a mock-up box just for the main image listing but you don’t need to package it. We’ve done that on a few products with awesome results. And if a customer asks about receiving no box, you can say that you have recently updated your packaging to reduce unnecessary materials and packaging waste for environmental reasons (although bubble wrap would be questionable ..?).
All in all, you are on the right track to ask your ideal clients what version they prefer, and if it”s black, then you’ll just need to be creative with your main image to stand out amongst the other black lights.