Selling items for less than they cost to produce is known as "dumping" in international trade (where it is generally disallowed by trade organizations) and can be illegal in the US if the intent is to eliminate competition [0]. That last factor can be hard to prove, and I don't think the FTC is doing much about anticompetitive behavior these days.
[0]: https://www.ftc.gov/advice-guidance/competition-guidance/gui...
The Biden admin went slightly harder against anti-competitive actions and anti-consumer actions by companies and all the billionaires freaked out and poured money into Republican campaigns in 2024 in order to roll all that back.
This instance of spoofing is notable for being the first that I know of that wasn't primitive vector art or text, but a raster image!
In that area of Florida multiple receivers would have picked up actual ADS-B broadcasts. ADS-B aggregators do have various anti-spoofing measures, but they're not impossible to circumvent.
The only case of actual RF spoofing of aircraft transponder signals that I know of was actually done by the U.S. Secret Service, which interfered with passenger jet collision alert systems (TCAS) by apparently broadcasting bogus signals near Ronald Reagan National Airport (KDCA): https://nymag.com/intelligencer/article/aviation-flights-whi...