MUST Use Buyer's Agent???

[Brendan Harrison]

I am submitting an offer today on a property in the Seattle, WA Area. The listing agent is telling me I need to have a buyers agent and I cannot submit an offer on my own. Is this true??? I have never heard this before. The listing agent is also saying that the seller already signed an agreement to pay 6% in commission fees no matter what. I was under the impression if I made an offer without a buyers agent it would essentially strengthen my offer by 3%. Anyone familiar with Washington state real estate law that would have an answer? Thank you for your time!