My friends and I use what I'd call a "Expected Racket Value" variant for our games. For example to start a 4 player game we set up the values as suggested in the rules (6k in diner through 30k in docks) and then place the remaining racket money values off to the side organized in ascending order left to right. During the business phase show of respect, whoever wins the racket rolls a 6 sided die, if a 3 or 4 is rolled the expected value stands and is collected. If a 1 were rolled the value would be downgraded 2 levels from the expected value showing in the racket to where it would fall on the value track that was placed aside in ascending order. i.e. the diner has an expected value of 7k and a 1 is rolled, 7k falls between the 6k and 8k showing in the unused values and after downgrading 2 spots becomes 5k which is collected by the winner of the show of respect. A roll of 2 would downgrade the expected value 1 level, a roll of 5 would upgrade the expected value 1 level, and a roll of 6 would upgrade the value 2 levels.
I feel like it adds a little more variability to the game and doesn't make any one racket the sure bread winner or leftover scraps. I believe our last game kitty's was as low as 14k at the conclusion of the game.
We also attempted with a 10-sided die:
4-7 = expected value
1 = 3 levels down
2 = 2 levels down
3 = 1 level down
8 = 1 level up
9 = 2 levels up
10 = 3 levels up
This shakes things up a bit more, despite a slightly higher probability of the expected value holding up.
Overall I'd say it's similar to the FBI during any one game. Can have very little impact or certain rackets can snowball in one direction or the other.