Some people buy car fax services when someone is in the process to buy car. I think it will have time frame to use or number of car fax reports.
If you are lucky some one have that services available same time you are too. In last 2 years I was lucky to get one car fax report out of 10-12 request.
My suggestion is do not solely depend on sajha for car fax report. If you are buying from a dealer they will provide it to you not sure the individual seller can provide you car fax report.