If you are in professional sales -- i.e., you sell for a living -- the very first thing they teach you in any kind of sales training is to control the call. The salesperson has to initiate, direct, and control the conversation -- topics, pacing, everything. The first step on the road to nowhere is to let the prospect take the conversation where he wants it to go rather than where you want it to.
This happens in selling professional services, too. If you're discussing working with a new client, and he announces that your hourly rates are too high, the entire conversation can easily become about that. Not good.
In sales, dealing with objections is its own little discipline, known as objection-handling. There are all kinds of techniques for this, but the key to all of them, as pointed out in a recent post in The Selling Sherpa, is anticipation. After you've been at it for a while, there should be almost no objections you haven't heard before, and you should have an effective, convincing response already thought through and in your memory banks to use whenever you need to.
Most people who are selling professional services don't do this. They just sort of wing it. Bad idea. Take the time to start tracking the objections you hear, and mapping out your responses in advance. This will make your responses much more effective, will prevent the conversation from being hijacked, and will also make the entire sales situation much less stressful. Plus, of course, it will keep you far away from the drain.