If you don't mind haggling, this how I do it. Determine the invoice price of the vehicle from NADAGUIDES. That should be easy since it's a Toyota. Also check to see if there are any rebates for the model you're interested in. Toyota also has a 2% holdback on base MSRP. That is the starting price offer. Dealers will also add the dreaded "Handling Fee" which in my area is $500. You can also subtract that from your offer, but they will add it after you agree on a number.
For example; MSRP=$33,500, BASE MSRP=$31,000, Invoice=$28,000 Rebate=$500
Your initial offer should be $28,000-$500(rebate)-$620(holdback)= $26,880
You will need to determine what you want to spend on the vehicle and be willing to walk away. I know the Tacoma guys are getting their trucks at invoice (not sure if they are factoring in the holdback or not) or just a few hundred over invoice.
What area of Washington are you in?