You're first question should be, "How much are you willing to pay?". And if they dodge it, it's not a good sign.
Edited to add:
Sure, be polite, but don't be trapped into 8/16/24 hours of interviewing over the course of a week/month/months before only to get a below average offer
Edited to add:
Sure, be polite, but don't be trapped into 8/16/24 hours of interviewing over the course of a week/month/months before only to get a below average offer