Product Bundle Builder — illustrative example

INPUT
Catalog: notebook N1 costs USD 8; refill R1 explicitly fits N1 and costs USD 3; phone cable C1 costs USD 5. Create a writing bundle with no discount.

RESULT
Bundle: N1 notebook + R1 compatible refill.
Quantity: one of each.
Listed total: USD 8 + USD 3 = USD 11.
Reason: the refill supports continued use of the notebook.
Excluded: C1 phone cable, which does not contribute to the stated writing use case.
Shipping and tax are not supplied.

REVIEW
Bundles should solve a coherent use case and respect compatibility. Check included quantities and pricing instead of assuming that more items create more value.

This is a teaching example, not a live execution record.