I think the bigger penalty is being called out for flopping.
It might be bigger but its still close to nothing. $5000-$50000 fines for people making $10-20 million a year is the equivalent to nothing, especially when the league is paying the players extra for playing in the playoffs. As for being labeled a flopper, what does Lebron or anyone else care about that? The man has already done an half hour television special to announce his free agent signing and had a pep rally to announce his arrival in Miami. He's had much, much more serious PR problems than being called a flopper.
Seriously, this whole anti flopping policy has zero teeth. Want to enforce a rule, give the punishment teeth and a bite. The NBA has more serious penalties for sitting players who they expect to play on national TV, for making hand signs, and tapping a ref during a timeout while telling him a joke than they do for flopping and ruining the game.
What's your "bite" look like, then? I mentioned suspensions for repeat offenders - the league already has that policy but I'd move it from a 5th offense to a 3rd.
Money - real money - or playing time are notoriously the only sure ways to motivate players, so beyond making the fine a % of salary, which the NBAPA would never agree to, suspension seems like the only way to do it.
Next game suspension. If you do it a second time, 2 game suspension. Third time in one season, you are suspended for the rest of the season. In the playoffs, start with 2 game suspensions.
Think Lebron or West or anyone in a regular playoff rotation is going to even try to flop in the playoffs if the think they could be gone for 2 games in one series and cost their team a shot at a championship? I don't.