Why are you immediately jumping to reneging?
You have an offer in hand, with a timeline. Continue to apply to other jobs, network, go to career fair etc. If some other interviews come in, ask for an extension from the original company. This is much better than just accepting at the 30 day deadline, then interviewing with others, and possibly reneging. If you need another 30 days, ask for it, and ask for it sooner rather than later. To be super specific, ask for another month at least a week before your deadline is up.
(Although I have taken both my original offers out of undergrad/mba, I have had extensions on both, and seriously considered alternatives before choosing)
To clarify why I said what I did, reneging does make the university look bad. While not as big of a deal at state schools, and for undergrad, it still leaves a bad taste in recruiters mouths, and can definitely impact future recruiting at ISU. This is especially true if they are not hiring very many students per year from ISU, which I assume is the case based on salary and location.
Lastly, I work for a company based in Seattle, so now I want to know who it is..