Mystery party costumes for tycoons, entrepreneurs, heir/heiresses, or other wealthy character roles:

Unlike the celebrity character roles, which are potentially just as rich as these characters - these roles are all about flaunting the Benjamins, baby! These are designed for you to display your character's success and bank accounts. For any of them, you can wear a money suit, high roller costume, and any of the accessories to make you look super rich and successful - but in an extra cheesy and cheeky way. It's a party, not real life, so exaggerating stereotypes is expected. 

For the girls: a formal sequin or beaded gown coupled with a faux mink stole and large costume jewels (statement pieces) and maybe even a tiara.   A handbag with fake money sticking out of it - you just have so much, it's seeping from your pores.  The money boa is a hilarious, cheeky prop. If you buy some fake money, make a hairpiece out of it by creating a design with the bills, gluing them on a barrette along with some rhinestones and a few feathers or flowers to match your dress. Because dahling, you have enough money to spare for this. 

For the guys: wear a suit or tux (the money suit is great) and pick up some fake money and have it peeking out of your pockets or carry a money bag with you - you have so much money that you like to carry a substantial amount with you in case of emergencies...or if you decide to buy a sports care with cash, because why not? 

And then, you can always go over the top with a high roller suit with a money cane and dollar sign jewelry.

How are you different from the celebrity characters (i.e., movie stars, rock stars, pop stars, etc.)? Well, there could be some overlap with the celebrity characters, but your purpose is to have money and success dripping off you - your clothing should look expensive (even though it's not - that's expected with costumes), and you should accessorize everything possible to flaunt your cash. The exception to the clothing looking expensive is if you opt for a money themed shirt/suit/dress, etc. Then, you can claim it was made for you out of real hundred dollar bills. 

A celebrity character just needs to stand out and look flashy - but a tycoon or entrepreneur's appearance needs to scream all three - rich, successful, and famous.  A celebrity could lose their spot in the limelight with their next film that goes straight to streaming, but you are the real deal.