Simply put, there are none.
And why would there be? The services of a bond originator (also known as a home comparison service) are free, as the bond originator receives a commission from the sale.
Using a bond originator also requires very little effort on your part. All you have to do is submit the paperwork, and they will handle everything else; dealing with the banks on your behalf and submitting your application to multiple banks.
They will then present you with packages to compare, so you can choose the one that best suits your requirements.
So a bond originator can save you significant amounts in the long-term, while costing you nothing.