How to buy sample exam from CFAI?

I am trying to take one but i see no link to pay for exam… once I login it takes me to testing site and no exams there.

anyone has done this?

I dont believe they sell exams. About a month or two before your exam date they will make one available for free

When in test trac you need to select the heading from the drop down menu, something like " CFA Level 1 2013" the two availiable sample exams should appear below.