It's brutal out there, kids

I wanted to provide an update on my job interview.  Following my motto of "if you're early, you're on time; if you're on time, you're late; and if you're late, don't bother", I showed up 15 minutes early.  I asked the lady at customer service and she directed me to wait in the cafe for my interviewer.
After a few minutes, a very nice lady greets me and we sit down to start the interview.  She mentions another lady will join us in a few minutes because "she's the cafe manager".  OK, I thought, a second opinion.  The interview progresses and it's going well.  Then she asks me why I want this job.  I say that I love reading and I enjoy working with customers on a daily basis and this blends the two together.   Good answer right?  Well it would have been, except I'm apparently interviewing for a cafe assistant position.  You know, a Starbucks barista but inside Barnes and Noble.  Not exactly what I was picturing.
The interview continues, it is going well, and we come to the part where I get to ask questions.  I ask a few about training and working environment and then I ask the pay.  $7.25/hour.  And the only reason they interviewed me was because I had so much sales experience.  It's part time, not even 20 hours a week, but eventually it could be full time where, because of all my experience, I could make up to $9/hour.
So after an hour interview with 2 people, a lot of questions, and confirming my references, I leave feeling like I got the job.  By the way, this was one of the most intense and thorough interviews, ever.  But the only problem is that I'm not sure I even want this job.  I didn't realize it was in the cafe, or that it was minimum wage, or only 15 hours a week.  That's only $100 before taxes (can they even tax that?!?!).  And let's not count our chickens before they hatch... I haven't even gotten the job yet.  If I turn down this job, can I still shop there?