If you are ok with working as a photographer for a company then I think the best way to show this is have a photographer bid on your next job or look at what photographers are willing to be paid for your job. Then look at the cost of a D7100, with lenses. I'm sure you already know what is the better idea. That's why you're here. The D7100 will last quite a while and the glass is superb. You would spend under $3000 dollars, with no need to pay another person, who could easily charge that much for just 1 commercial shoot. As long as your skills are good, you could make this a fun time at work while working. Just make sure that your superiors are happy with your photos and they will see that you can do the job as well. This could eventually turn into an in house opening in your company.