How much do people get to host parties?!

I would not go with an hourly wage I would set a firm price say $100 and say that your services are available for a 5 hour block of time. This is due to the fact that you will be spending more of your own time planning and researching games, decorations etc. The price should reflect what you expect to make per hour plus any supplies that you will be expected to bring. By setting a block of time it helps you to set limits as to when the party will begin and end and actually gives your time more value. You can also expect to receive a gratuity for a job well done. Good luck to you.