How much and how to ask my buying agent to rebate?

[Rudky Martin]

I am new in real estate and about to buy my first house. The house’s listing price is 800k. I found this house in Redfin and saw it by myself in it’s open house alone. My buying agent was involved only after I decided to buy the house. He gave some suggestions mostly to encourage me to buy the house with higher price than the Listing price. He told me he spent 4 hours running a comparable tool to generate a report. 

Now when I ask him a rebate in case I can get the house. He said that there is no rebate because he would suffer heavy taxes and his net earning from the deal is very little compared to his effort.

Can I ask him to send me a copy of his agent contract so that I know how much percent of commission he will get?

On average how much a buying agent will rebate to the buyer?

Thank you.