The .025% comes from Oregon being 1/100th of the US population, right. It should be adjusted for spending, but close enough!

You ask if a company will just adjust pricing for Oregon given this cost. I think some will, some won't. For the example of Apple, they won't. Do you see iPhones for $399 in one state and $416 in another because shipping costs are higher or rent is higher in a particular Apple store? No, you don't. Or more directly, there are some states with higher taxes than others, and the iPhone costs the same in all states. So there is a class of company that will price nationally and spread the costs out nationally. Other companies will not... such as a grocer that adjusts prices for every market. 

If we wanted to figure out the cost:benefit ratio we would need to ask how much tax will be collected, and that seems well estimated, and how much of an increase in prices we will see. What are the top companies in Oregon in terms of sales? Maybe we could figure it out.