So lets say I want to avoid all bad non interested in buying people. There clicks cost me money. Would it be wise to write a ad like this: Learn how to lose weight fast ------------------------------------ Learn how to lose weight with this ebook for only $49.99
It depends on the circumstances. If other ads are selling the same product, and you have the cheapest price - tell people. If other ads are selling the same product, and you DON'T have the cheapest price - try making your appealing in other ways. If your landing page is great at convincing people to buy, don't put the price in the ad. Ultimately, AdWords ads are in "Ad Groups" - use this to your advantage by doing A/B testing to find out which converts best for you.
I recently tried to experiment and added the price to the title of my ad and both CTR and CR increased. But I'm totally agree with enginez, before mentioning the price I checked other ads for the same keywords to be sure my price is lower.
You will lose all potential customer's clicks. I mean the people that were not going to buy anything from your site unless they got to it. There's also to consider that you will lose ctr and so you will end up paying more for the single click.
My conversions always improved when I added price to the ad group. It's just another step in the presale methodology which can offset any CTR problems. But really, who cares if you get less click throughs, as long as you have higher conversions.