There are two rates: 'pro', and 'pro bono'.
Every job you do needs to come under your 'pro' rate. No referral discounts. No friend discounts. No family discounts, no ’deals' swapping services with other freelancers. A professional charges a professional rate.
As a professional its important to charge a pro rate and get used to the value of your work. when you are established and want to take on free work (pro bono) THEN you can pick and choose which projects you will do for $0, but theres not rate between full, and $0. Its also common when working with charities to invoice the pro rate and then donate 100% back to the cause if you aupport it. This invoice+donation still lets your client understand the VALUE of what your providing.
Clients paying money, but less than you are worrh will degrade your perception of your work, and are usually the worst clients you cN have because they ALSO dont recognize the value of what youre offering.
Only take on pro bono projects that you can afford, and when youre starting out you usually need the money.
My advice is be up front with people if you dont have a large portfolio, but focus on the value you can provide them and collect the full amount that is worth. They arent payong you for work you did for oters, ONLY what you do for them.