I was a commercial photographer for 55 years and have seen some pretty large bubbles in view camera lenses. I’ve owned several that the bubbles were quite visible but even those there was absolutely no impact on images
As to used value, knowing what the photo world is like today, it may reduce the resale value. The thing to do is simply keep it. I own one and it’s a tremendous lens so just make some great images with it and forget about the bubble.
A bubble in the glass will absolutely not affect the image quality in any way. Whether it will affect the resale value is hard to say. If you are concerned can you not send it back?
