i wont believe it till i see it! I think it might just be a lie you mean to tell me that someone is willing to pay that much for getting a site visited? Plus you have to understand that Google gets his share, so the person advertising on adwords must have set his ppc as much higher than $52 per click. 52 would be just the small commission you get!
One of my site : "home loans" get 23$ for 1 click and on that day 4 years ago i made 76$ from that site. After that so many site of my get 5$ 7$ 12$ per click on average.
there are diferrent categories .. i guess financial and medical ads give the most cost per click for some keywords rate is around 110$/click
king99 your right in medical niche keywords are $110+ so i think the highest would be about $110 - $150 dont think they would or has been a higher amount for one click my highest for the record is $7 but it all depends on your niche and keywords you use and what standard your content or your site is like.