Overweight bag fees suck. You can take out the extra stuff, but if you are already at the airport, where will you put it? It’s better not to overpack the luggage in the first place. A luggage scale can help prevent overpacking. Or to back up your argument with the gate agent:)
Here is the one I like:
This slick tool has up to 110 lb capacity. An LCD display, durable stainless steel design, auto shutoff , auto-lock display and a long life lithium battery make this scale a great investment.
Read reviews and check prices: Tarriss Jetsetter Digital Luggage Scale