I will always ask what my pay rate or salary will be, if they have a problem with a possible employee wanting to know what they will be paid then i wouldn't want to work for them anyway, its a competitive market out there job wise meaning employers can often pay minimum wage and still easily fill positions but based on experience knowledge and qualifications i wont be working for minimum wage. I think its fine to ask about pay as long as you dont do it in a rude manner. Asking things like " and what sort of payrates do you have" and things like "What is your promotion scheme like, eg do you prefer to promote from within and what sort of growth opportunities do you have" are valid questions that will show you expect to work hard and move up, but you also expect to be compensated for your hard work. Just my 2 cents