Average real estate agent commission % in Northern NJ?

[Jenny L.]

We relocated to NJ last year and do not own a home, thus are unfamiliar with agent commissions here. What is the average buyer’s agent percentage in affluent Bergen county? I know "it’s all negotiable” but no need to beat around the bush.

We've run across a few FSBOs using a flat fee MLS listing (we assume) and see in the property description: "2.5% to buyer's agent" or "buyer's agent 2% commission offered". Is this on par? In a run-of-the-mill sale with both sellers and buyer agents, is 5% total commission the norm, then split 2.5% each? Lower?

Further, while visiting an open house, we overhead that commissions on very expensive homes (1M+) are lower. Insight on this? What percentage lower? 

Thanks in advance!