The quality score may vary over time as your overall site rating changes, generally the overall landing page quality and ad copy and landing page content matching are quality score factors, there are other factors, your previous ad history may be one as well. I would not get too caught up in the price and quality effects, typically your real cost will be lower than the bid.

Broad match is probably not a good thing to use, instead select multiple longer long tail keywords like "dog urine removal" "cleaning dog urine" with phrase or exact match, ideally the phrase will appear in your landing page.

The strategy behind the Google adwords is it generally use for the keyword research and to find the density of the keyword.It is the best tool for the keyword research.

Google adwords basically keyword research of a web site.

Which keywords you should use is depend on the user mindset toward buying of your services or product. don't count it of the $ 1.50 or $ 2 but count on which keyword can give you buyer try to make the good quality score for same. First page bid estimate itself is a estimate and not exact value it also depend on the run time competition for keyword at the time ads running.

I enter a keyword, let's say dog urine, with a $1.00 bid. Below it says First page bid estimate: $1.75. As a broad match, the quality score is 3-4/10. It goes to a web page of my carpet cleaning website that gives some diy info about dog urine clean up. Then the page goes on to say if this has not cleaned up all of the urine (it rarely does, but some is better than none) that you should call a professional, me. Then it goes over what I can do, techniques, tools, equipment. Sometimes I have to clean and seal the floor below the carpet, replace the pad and use specialty tools, techniques and products to get this remediated.

First off, I can't figure out why the score is so low. Another keyword, say dog piss (let's see if yahoo censors (p!ss) isn't even on the page or metatags, yet it scores 5/10.

Then come the most confusing. Some words that score low, when you change them from broad to phrase match, the First page bid estimate: goes down when your score went up. You went from a lousy 4/10 to a good 7/10 and the cost drops from $1.75 to $1.25. That makes sense, you have a better score so you will not pay as much. But sometimes when you go to phrase and your score more than doubles, from 3 to 7, your cost may increase from $1.50 to $2.00.

Would it be better to leave it at 3/10 and pay $1.50 or 7/10 and pay $2?

I don't fully trust the first page estimates. I have keywords that have First page bid estimate: $4.75 and my bid is $2 yet my page rank average is 2.7, so obviously I'm