It's always good to make sure about the cost of specific procedures, because sometimes there are extra charges for things you would think were included. (Like, the "basic" IVF at my clinic only included a 3-day culture after retrieval. So if you went out to 5 days it was extra.) Stuff like assisted hatching, ICSI, freezing embryos, etc. was also extra.
Some clinics can help you out with extra meds that people drop off, so I'd check on that. (Unless you are going through insurance.) If you are self-pay, they sometimes work with financial groups that offer discounts if you qualify.
I asked about the specifics of the cycle, like approx. how long was each stage, so that I had an idea when retrieval/transfer would likely be. I was also interested in the protocol because I love to research.
It's good to ask about the clinic's success rate for your age group, and more specifically what they think your personal chances are.
One last thing that I didn't think to ask until after I'd already started stimming, was what is their policy if you only get 1 or 2 eggs? Some clinic's will automatically cancel the cycle, so it's good to know that if you wind up being a poor responder.
Hope that helps!