Finding affordable Keywords for CPA Campaigns

I've recently been accepted at a few CPA networks and started running a few campaigns across a variety of niches. Down the road I want to get into Media Buys etc., but for now I'm focusing on Pay per click to buy traffic. I've already checked out several recent CPA Courses including Zero FM, Arbitrage Consp, Comm payload etc. to help with the all-important Offer selection.
By and large, the courses typically emphasise -
1. Choosing popular niches
2. Using various trending websites to identify up and coming markets in those niches, and
3. Assessing the offer landing page itself and how attractively it is designed.

But it seems to me that after estimating the Earnings Per Click for an offer, it is critical to identify whether any reasonably targeted quality adwords traffic can be bought at a potentially profitable cost, in sufficient volume.
i.e. It doesn't matter whether an offer converts at 33% with a commission of $30 giving an EPC of $10 - if our clicks cost $20 then we're not going to be making much money!

Of course I'll be using my Philippine contractor to build a Wordpress Landing page to boost my Quality score and get clicks as cheap as I can, start bidding high to get a good Click through rate, etc, etc. But from my research so far it seems that the majority of 'obvious' keywords for the majority of offers are too expensive to offer much hope of a profitable campaign. In which case, surely it's a waste of time and money to even attempt to run Adwords test campaigns for those offers & keywords...?

So I'm concluding that the whole trick of using Adwords with CPA Offers is using lateral thinking to find related, not so obvious keywords which are much cheaper, but can still lead to plentiful conversions using a cleverly constructed Landing page. Kenster's excellent CPA Rages to Riches mentions this, another example being Amish Shah's Magic Bullet Trailers where he bids on MSN Messenger keywords to promote a Smiley campaign.

So if this is the name of the game, then fine I'll head in that direction, but so many courses still strongly imply that it's more of a numbers game i.e. crank through as many offers as possible with the 'obvious' keywords in the hope of finding gold.

What do all the $1K-a-day Warriors reckon?