You will get your prices going up, by an independent system. The buyers pushing your prices up will get the lower price they got before the rise for a period.
A system where you join and set your current price for your services. These should reflect your actual market price at that time. You now invite your best customers to vote your prices up based on their experience with you. This becomes your new price for all customers, except those who voted your price up – they still get their current rate for a period you decide on. This dynamically builds up your prices (and as a bonus is also a testimonial by your clients who vote), in an objective way, so new customers have a good reference as to why you charge the amounts you do, and current customers have the motive to help you. You control the amount of price hikes that can be voted, and also the frequency because you don’t want your prices to escalate into counterproductive heights.