I have been to quite a few birthday parties in my time and the amount of children whining, saying , "that's it, there's no more" is astonishing.
I purposely wait until the end of the party before we start opening presents, I don't ever want my children to think that their parties are focused around presents. In my opinion, birthday parties are meant to celebrate your child's life with family and friends. Now do I occasionally spend a lot of money throwing the parties, yes. But I have never expected everyone to bring a gift. You coming to join in on the festivities is good enough for us.