Perplexed in the Job Search

This job search has got me confused.

I'm looking for a full-time job in a subject matter reasonably associated with my background, with reasonable work conditions, and with a reasonable salary. Seems, well, reasonable, no?

I am *this* close to a formal offer of a single course instruction at a local academic institution. This would be back in academia. I have no problem with being back in academia, but the prospects of a full-time job in this city are negligible. This course, well, it would be good for my ongoing cv development if academia is the way I want to go.

As a single course, though, it's not enough to pay the rent, and the one-day obligation could prevent me from getting a full-time job. And, would it really help me break into the academic jobs in this city? One course? I don't know. Am I willing to work in academia for basically minimum wage (considering the part-time status) for the years it would take to maybe get a full-time gig? No.

So what do I do? Do I take this course, since it's better than nothing? Is it really better than nothing if it prevents me from getting a full-time job? Do I piss off the institution by pulling out after getting the offer? Is this course even what I really want?

Why is it so hard to find a reasonable job with a Ph.D.?