The cost of purchasing a course related to IT proffession is quite on a high side in our world today, still lots of competition out there, a lot of people searching for clients using different advertising methods making it harder to find clients.
There are hundreds of web where you can find top class clients like Shopify,Godaddy and much more but i will recommend you to find it in Facebook.
There are many big groups in facebook where world class Clients available. First you should get trials from IT clients to avoid from scam.