Why would you block ads anyway? Adsense is going to determine which is the best ad to display ion your site and once a certain ad is shown, meaning Adsense sees it as the best ad to display in your site, and the amount is one of the factors it consider when selecting it.
We all know that Adsense advertisers come into bidding process. They bid for prices so their ads can be displayed in a certain page. When ADsense decides which ad to display, it will select the highest bidder for that niche. So there is no such thing as "low paying ads" for me. It is the niche that determines the value of the ads displayed in your site.