That happened to me as well. Only mine were about $1 clicks and dropped to about $0.2 - $0.20. My content is basically the same. I did some link exchanges and that's about it....could it be the text included in the link exchanges?
Wouldn't have anything to do with the links to the page. If you have more than one block of AdSense on a page though the price per click you get could vary. Google will usually try to show the highest paying ads in the first block it encounters in your source. It's not inconceivable for the first ad on your page to get a few dollars while the last ad displayed to get a few cents.
kids were the high paying ads from the first few days you were using AdSense? If it was only in the first few days you were getting the higher paying ads it could be as AdSense spidered the site more it determined your topic was different than what they did in those first few days. It could also mean the main topic of yoru site is worth a few dollars per click, but the specific pages are on a slightly different topic that earn less.
Looks like you got hit with smart-pricing. Google has determined that your site's "quality score" is low. Unfortunately smart-pricing affects the entire domain and not just individual pages.
I think smart-pricing is an AdWords things and not an AdSense thing. The price of the ads you display on your site should be based on what the advertiser is paying.
