Answer
I would offer a starting salary that is average or slightly lower than average for the industry because he is straight out of college and this company has more to offer than large paychecks. However, if he works hard he will receive bonuses and compensation for his loyalty. If I was Gabriel then I would accept a salary lower than the industry standard because I would want to work for a socially responsible company and would take lower pay to do that. These two number could be the same but may be different due to different expectations for the other party. Giving Gabriel a higher number than your conscience and the company can afford does violate the transparent culture because everyone should be on the same page about expectations and worth. Any deviation from this culture could create a negative environment if individuals are being paid less than him.
Work Step by Step
Salaries can be a tricky place to maneuver. However, a company with transparency should dedicate itself to upholding its values. This means being fair with salaries and not paying someone more if they do not deserve it in comparison to their other employees.