How to click button with applescript using UI Element Inspector
Solution 1:
This is the easiest way...
tell application "Safari"
if not (exists document 1) then reopen
activate
set URL of document 1 to "https://itunes.apple.com/us/app/ibooks/id364709193"
delay 3
do JavaScript "document.getElementsByClassName('lockup product application')[0].childNodes[3].onclick()" in document 1
end tell