do a search on this forum and you will find many. some made $100+ a day.

make website which gives information based on high cpc keywords like hosting, insurance etc, and add quality content wait for few months to rank in search, you will easily make min 20$ per day!

VGM

Making 20$ per day from Adsense is relatively easy provided you have patience and right information and knowledge to move ahead.
First have a understanding of all about google adsense policies,norms ,what kind of website to make,how to search for keywords,how to bring traffic to website,how to promote website ,where to place ads and you will surely be raking in more than 20$ per day from Adsense.

You can buy one for about $5000-$8000.

Or do some reading, be prepared to invest ~$2000 into a couple websites (there's a chance that you'll make a lot more than $20/day) and get to work. It doesn't take long to get to $20/day.

Just focused on low competitive and high search niche, you will surly get their.

Find profitable keywords. Build a site with at least 10 pages. Upload your AdSense code. Start backlinking. Wait until the site is making $2/day. Repeat that process ten times.