First, not all buyer's agents are willing to consider contributing a portion of their commission as an opening concession to work a deal. Many are working for brokerages that are already taking a percentage of the commission and their are a lot of other considerations.
So there is no typical or average amount.
With that said, I just closed 2 transactions last week in which I provided both buyers a portion of commission to go toward their closing costs. Part of the consideration for me is how much time did I spend on the transaction - in other words, were they a buyer who was ready to buy, knew what they wanted, were highly qualified for their loan (or a cash buyer), and reasonable to work with.
If that is you, feel free to contact me tomorrow and we can further discuss what arrangements we can make - with me, the talk about pay less, get less is non-sense. I am in the top 1% in San Diego County in terms of serving the needs of buyers and sellers. I sell from the coast to Escondido to Santee to Chula VIsta.
CA DRE 01775528