If the right person catches a validated world record largemouth bass, and under the right circumstances, then I am confident that it will be worth well over $1 million.
The person needs to understand the situation, and be prepared for it. Live on-the-water, well-taken photographs with a quality camera are worth a lot of money for a long time. I would shoot as many different pictures as possible. If someone lies about the products that helped them catch the world record, it will likely backfire and hurt their financial chances. The path to the reward is to use the right products in the first place. From the perspective of the record bass, the right products will likely be necessary.
The more people that see the live bass at the lake, the better. Many states will not let you transport the fish beyond the waters edge. A violation will likely nullify the record.
If the angler is well-known (not necessarily a "pro") as a good stick, and the angler is presentable and has speaking skills, then there will be plenty of opportunities to earn a paycheck speaking at events. The magazine articles and public exposure is worth cash to manufacturers of products that played a role, but only the large ones with big marketing budgets and high-volume lure manufacturing capabilities will pay a lot of money.
Berkley can manufacture a ton of a particular lure in a hurry to meet the mass demand that is likely to occur. People who have never bought a fishing lure in their life will buy the lure that caught the world record just to give to the bass angler in their family or their friend. The problem is that most companies have no hope of producing the products fast enough to capitalize on the window of opportunity.
The person had better be prepared to be demonized. The fish will likely have to be killed, and kept frozen for later testing and verification. Even the carcass dimensions are worth money (to fiberglass mold makers, and for research purposes). The angler will get hate mail and speech from those who don't like the fish being killed, even though the person has the legal right to do so. Relationships will be strained, privacy will be lost, and people will come out of the woodwork to steal some of your glory and money. Jealousy will be encountered on a daily basis, and all the attention (wanted or not) will make the angler appear self-centered and egotistical just by relating their experience to those who want to know.
If the angler is lucky enough to be able to keep the fish alive, and legally transport it, the bass will be worth a small fortune to the venue that can display it and use it to attract people. Hopefully if caught in a state that doesn't allow live transport, an exception to policy (permit) will be granted allowing the State to transport the fish alive for research and public relations. Ideally I would love for the State Dept. of Fisheries be allowed to showcase the fish alive to promote fishing in general.
Of course, on the other hand, if the wrong person catches this record it could be the most expensive catch and nightmare the person would ever hope to have.
ciao,
Marc