What is the cheapest airline where I can buy tickets to go to Paris?

Answer 1

Do a search, enter your home town and Paris, and add cheap flight or cheap ticket.

If you have several airports near, check on each one.
And you can also go to a travel agent, they know which tickets to get you, you just pay a little extra for the service.

Answer 2

I don't think "cheap" is an option on international travel. However look at Delta's business class for good value.