What API can I use to retrieve HealthCare Data?

Question

I am looking for an API which provides the healthcare data of a patient.

What I am trying to do is:

1. User logs in to our website.
2. Then the user want to get the CDA data from his/her healthcare provider.
3. Selects the healthcare provider.
4. Provides the userid and password for that provider.
5. Our website makes a call to the API with all this information.
6. The API returns the CCDA data for that particular patient.

I have tried MedFusion and HumanAPI both of which are quite expensive. Can anyone suggest me something cheaper?

I don't want to go the web scraper way, as it can be cumbersome and buggy.