Take in consideration who the Johnson is, also. Each corp has their own specialties, and it can make the game more personable (and make the characters make preferences for one Johnson over the other), if you consider the source of the job in mind when haggling out a price.
It can build a new dynamic of suspense or choice, do they work for one mega when the job doesn't have their best interest at heart, because they're the ones that shell out the loot they like, or do they work for a different side (even if just 'hooding, which was mentioned earlier) who doesn't pay as well monetarily, but can help in other ways. Contacts or access to gear or medicine and teaching can go a long way. Even if somebody can't pay, per say, for a job, they might get them access to something they wouldn't otherwise have, and that might be better for them than having extra nuyen with nothing to spend it on filling up space in their sticks.
Heck, rewards could even come in the form of services.
I wholeheartedly endorse the idea of giving rewards that aren't just straight up injections of nuyen.