The majority of drug dealers would make more money getting minimum wage jobs than selling drugs, soldiers get paid less than the manager of McDonalds, and 99% of all football players will never play a single down in the NFL, so play for free despite the cost of transport and medical.
Crime is not, by and large, a lucrative field.
The average successful Shadowrunner will pull in about 6000 a month. Those who engage in globe-trotting style campaigns where they're the best in the world will make closer to 40,000 a run, but only get three, maybe four runs a year. Rookie 'runners are lucky to pull 2400 a month, with a weekly run netting each about 600 Nuyen.
This is why you always want to have a good reason for your character to run the shadows ... most could live a normal life and make the same, or more, than doing what it is that they do ... deckers and magicians being the big ones who stand out. One of the thing sthat you should always ask players is "Why is your character doing this?" If it's "To get rich,", well, they're in for a rough time.