Was talking to David Weinhaus today. He's running a mastermind group for HubSpot partners. He has 20 agencies signed up for it. In the last call, he asked the group, "Do you thank your prospects for their time at the end of a sales call?" 90% of them said that they do.
I suggested that he should tell them to say the following instead, "Thank you for your time today. Obviously, your time is more valuable than mine." (Yes, that's a joke. You shouldn't say that.) Unfortunately, when you thank prospects for their time, that is what you are implying. So, you might as well say it if you're going to continue selling the wrong way.
Instead - if you want to sell the right way - you should make it a goal for your prospects to thank you for your time. (They should really be thanking you for insights and for making them envision a better future state for themselves. But, most prospects will never say that.) In sales, the prospect should always be receiving more value in a call than you are. (When they do buy from you, they should expect a significant return on their investment too.) There should never be a time when you're thanking them, even when they are clients. It should always be the other way. If you're delivering value, they should always be thanking you.
As a baby step, stop thanking prospects for their time immediately. Also, when a prospect thanks you, you should say, "You're welcome." If you really want to do this right say, "You're welcome. What specifically was helpful for you?" If they can't tell you anything specific, then you're still not doing it right. But, at least you're not implying that your time isn't valuable.