bundles

Hi guys,
i've been looking around the docs, forums, etc. but i can't found out how to build my special case!

I need to build this:

PRODUCT WORKSHOP:

• All 4 sessions: 160€
• Session 1: 50€
• Session 2: 50€
• Session 3: 50€
• Session 4: 50€

Means i need checkboxes, and if the customer choose "All sessions" the others are inactive, or they can order individual ones. Also the full package has a different price than if you take individuals one by one...

Does anyone has this case, and can maybe lead me on the right way to go?

Thanks,
Tom

To learn the ECK faster by myself, I'm now trying to write a programmer's tutorial and an API reference in the style of the django documentation
https://docs.djangoproject.com/en/1.4/intro/tutorial01/

Are there good examples of modules using the ECK?

You can also help me with a hint about how to add and modify bundles using code. I didn't see anything about that in the existing documentation (but with mouseclicks, it's very simple).

Philipp