Its a tricky subject, and causes lots of anguish. The linked article below really reasonated with me.
Professionals Don’t Discount Their Services (And Neither Should You)
I've been following advice given to me; that your rate stays where it is, but you offer more for it.
For example, let's say you're a coach (Robert may have lots to say on this example!). Instead of dropping your rate, keep the rate and the length of the sessions, but include between-session email contact for free (if not already offered). If you've written a book; throw it in. If you can combine your services with another provider; create packages that include both services for a slight volume-style discount (but the rate for each can't be reverse engineered directly from the price). Change the overall pricing model, but so you still get paid the amount you should.
Not all will work for you, and some may strongly disagree with the actual examples provided; but your headline rate signals so much more about you than just a dollar figure.