Less rare could be a way to go about it, but the problem with RNG is there is a chance they'll never appear. Off the top of my head to keep RNG and guarantee all figures are collectable, is a rising find percentage. For example, over a ten day span, the odds to find increases 10% a day, with 100% chance on day 10, resetting once it's collected. Alternatively, hiding them in scenes you're guaranteed to see would be better, and give everyone a chance to get them all.
And an issue with clicker games is they can be very unfriendly to people who can't click rapidly or precisely. If that's the only way to earn money, they can't progress in the game. If it's a way to boost earning, then it turns it into a grind for them to earn it otherwise. Will there be other ways to earn money as the game progresses?