People who work at grocery stores, especially ones at the check out lines, I would think might have a bit of an advantage with grocery item pricing, especially if said employees live in California which is where the show is taped.
Ditto for car salespersons or people who work at retail stores for smaller prized prices, such as ones used in Bonus Game, etc.
Teachers might make for great contestants, e.g. Ted Klaussen.
I forget the one contestant's name, but I think he might have been on the autistic scale. He had an exact bid of $2,148 for a scooter and then played Buy or Sell flawlessly, becoming that pricing game's biggest winner. I do not know if this young man was employed or not.
I don't know how many, if any, professional gamblers ever make it to the show, but they are very in tune with statistical probabilities which might come in handy with certain aspects of certain pricing games.
Those who are not employed, be it college students, retired people, or those who simply are unable to find work and who are home and able to either watch the show when it airs or stream it at their leisure could make for ideal contestants too. The basic premise of the show it seemed way back in 1972 was geared primarily for housewives of the era, but that is by far a bygone era.