I recently did what Playfelt suggested about searching on this site for rates of daycares nearby and found that they were all charging $35, so all my new clients will be charged that. Currently my clients are paying $32. I honestly don't think you will find many people interested in paying $40 as $35 seems to be the newest highest price people are charging (I hope that makes sense).
When my daughter was in daycare I paid $32/day plus stats but nothing for vacation time.
Hope this helps.