I find for guys it's more practical things like cost, how long to set up, what does it look like and will you play XX for me
For girls it's more: will you make my wedding special, will you make it fun, will you make it memorable then how much (followed by HOW MUCH

) 'Well you want it to be special so that's my special price'
I find that the guys who make an enquiry are given the task of organising the entertainment as a token gesture and have very little say in much else - if this is the case then a comment along the lines of how important his one task is and how everyone will remember his choice long after the event doesn't do any harm.