So to be a net drain, illegals in Oregon would need to consume roughly 130 - 150 million dollars in services.
They only need to consume 130-150 million to be a net drain? OK, let's start with schooling expenses. We have to make some assumptions here, so lets assume that only half of those 175,000 workers (87,500) are in families with children, and that each family has 2 kids (giving us 175,000 kids). Both are low estimates according to my experience. Now, according to the
Oregon School Boards Association, spending per pupil in Oregon in 2000-01 was $7,357. $7557 x 175,000 = 1.287 billion dollars. If we wanted to, we could assume a ridiculously low number of children for 175,000 illegal workers and use the figure of 1/10 of my original estimate, or 17,500 children, and we would still have $7557 x 17,500 = 132 million dollars. We've already reached your figure.
However, now we're going to add incarceration costs. According to
this , illegal aliens cost Oregon 31 million per year to house deportable criminal illegal aliens.
Now let's add medical costs. Apparently stats on emergency room use by illegal aliens are hard to find for Oregon, but Congress's Emergency Medical Treatment and Labor Act apportions reimbursement for unpaid medical care to each state in proportion to the number of illegal aliens, and while New York received $12 million and California $70 million, Oregon received $2 million, which covers a fraction of the actual cost.
As you can see, these basic services have already surpassed your minimum requirement for net loss, and that was using low-end estimates. However, there are many hidden costs to the presence of illegals as well: the printing of government documents in Spanish (and other languages), the rise in cost of automobile, health, and life insurance based on the assumption of cost burden of the uninsured by the insured (illegal aliens are certainly uninsured), cost to citizens who are victims of illegal alien theft, rape, robbery, drunk driving etc. You get the idea.