Pricing is one of the most complicated issues in business development. It is so complicated that you should research the topic by reading the trade journals in your profession.
If you are in a firm, the management of your firm will probably determine your pricing. If you want to lobby for change, you need to be very clear about the impact of any changes.
If you have control of your pricing structure, an important issue is how much you think you are worth. If you think you are charging too little, you will feel frustrated that you are losing income and will feel motivated to increase your rates. If you decide to increase your rate, you may want to experiment with some clients before you make any over-arching changes.
If you think you are charging to much, you might feel inclined to lower your prices, but before you do, you might want to consider increasing the benefits you offer and make sure that you are skilled in communicating all the benefits your offer.