Does an aggregator engine exist in nature?

Question

Online shopping

Does the right aggregator engine exist in nature, or, as always, do you need to do it by hand?
What you need:
- Personal accounts of suppliers
- Uploading prices by suppliers as YML / XML
- Transition from the product page in the aggregator to the supplier's store, accounting for transitions

Answer 1

It hardly exists , because a solid part of the functionality should not be in the form of infrastructure, but as a competitive advantage