Perhaps the 2nd most asked question we get is "Will sharpening my broadheads change their weight enough to make a difference?"
To answer this question we made a video of a VERY dull replaceable blade being sharpened and weighed before and after. Here are the results.
A far more precise scale would be required to capture the very tiny amount of weight change due to sharpening but suffice to say the impacts on weight due to sharpening are so small as to not matter in the grand scheme.
If a blade is damaged or bent, certainly throw it out but if its only dull, there is no need to buy more blades, you have the ability to sharpen them yourself and return them to service.
FYI, there are 437.5 grains per ounce. After testing broadheads (lots of them) over the years, broadheads vary quite a bit in weight straight out of the package. Some as much a plus or minus 10 grains.