You are on the right track. What you want to find is keywords with high volumne and high CPC. Since it's hard to find both, you then need some mix of the two. I prefer to go for keywords that have high CPC, and by high, I mean the higher the better, like $15-$30. Then I try to find some that have at least some traffic like one green mark, or like an estimated cost of at least $1 per day. This means they expect 1-2 clicks a month. I may not get that much, but I only need one click a year to pay for my registration fee (if I get that much, which is unlikely).
If you find a phrase with low traffic, it may not have enough on Yahoo to show up, so you won't get any bids from them. But if it looks good on Google, I would not worry about Yahoo much. I'm not sure because I don't check yahoo for bid prices, only searches.
Estibot is one of those automated tools to determine what a domain is worth, and from what I have seen those tools are interesting, but that's all. The amounts always seem too high to me. (Hah! I just checked a domain I sold a few months ago. Estibot says the value is $140. I was offered $450 for the domain, and wound up selling it for $1,000.)
But I assume you are trying to figure out what the domain will make while parking and not what it should buy or sell for?
One trick that people don't seem to understand is that when you are using AdWords to check, it is set up for advertisers, and not domainers. Therefore, I feel your thinking needs to be reversed a little. There are two things that I recommend:
1) If you run an estimate for something in adwords, use $99 as the max bid and $9999 as the budget. This will make sure you see the highest possible bids and the highest amount of traffic possible. If you don't do that, then always use the same numbers so you get consistant results.
2) When you check keyword phrases, use the brackets for an "exact match". Remember that your domain is a narrow match and not a broad match. You need to zero in on what your domain will be found for and not what an advertiser expects to be found for. Reverse that thinking. This will show you more realistic numbers in my opinion.
Checking something like "home loans" without the quotes will give you much different numbers that "[home loans]" also without the quotes. And "[loans home]" will also be different. Which brings up a good point, if you are checking a phrase, try reversing it. You may find there is search volumne and that there are also some domans that are available.
People also do a search in the Google search engine for domain keywords. I still don't get this since it has NO meaning for how many times something is searched for. Also, when people do this search, they just use "home loans" without quotes. They don't understand that what you are telling Google is "show me all the pages that have these two words somewhere on the page". If you are going to do this kind of search, do it WITH the quotes, since this tells Google, "Show me all the pages that have these two words together and in this same order.
