Isn't that obvious? Better jobs, higher pay, higher requirements. Some jobs, for example, might require a divine girl with the temperament of 90+, preferrably oriental, for 12 hours, high risk, $200k payment.
Warning: if the $12k required to purchase this package is some serious money for you, don't - the requirements might be so high you won't even get your money back. Only do it if you can manage to - at least once in a while - clear the previous level to the last job.