Cheap way to do PPC?

Hello,

I'm new to the world of internet Marketing. Basically I'm looking for a way to quickly test weather a product will sell BEFORE spending the money to produce it. I was told to create a web page, then drive traffic to the web page via Google adwords for about a week to determine if the product will be lucrative enough to warrant the advertising and production costs. The problem is that the cost to use adwords to drive traffic is prohibitive....over $4.00 a click....I was told to make sure it was under .20 cents a click while still coming up as one of the top 4 results. This has proven to be very difficult....I have read many articles on optimizing Google adwords through seeding your website with your keyword(s), as well as making sure that your adds have your keywords embedded within the copy. I have done all of this but still have a very poor quality score (3/10).....I have contacted Google and they informed me that there is nothing wrong with my adds or landing page relevance but that the system would need time to gather information before my quality score would improve. Who, however, can aford to pay $4.00 a click untill there system "catches up" so to speak. Is there something I'm missing? I'm looking for a cost effective way to "mini test" if my product will sell. Any suggestions?