Interview at a coffee shop?

Hello. I have an interview tomorrow with a start-up promotion company. They don't have very much web presence other than a tumblr, myspace, twitter (i think) and a facebook page. Many people say to be wary of interviews in coffee shops because it shows that the business probably can't afford to pay a salary to another employee. I did see that they were hiring interns, but I think I made it pretty clear in my email inquiry that I am looking for a paying job (Not looking for much pay, just enough so that I can pay rent and bills while gaining experience). I said in the email that I was looking for employment and asked if they were hiring. I have a degree from a top public university and I have had job experience since being out of college. Do you think they would actually schedule an interview for me if they are just going to offer me an internship or a job without pay? It seems unrealistic that they would be able to pay me, but just as realistic for them to think I would accept a job with them for no pay. What do you think? And how would I politely decline if the latter is the case? Thanks so much for the answers!