Trying to re-create a form

I recently (6 months ago) converted from ASP to Drupal. I had a form on my old site for our Annual Golf Outing. I am having issues trying to re-create this in Webform/Drupal. Can anyone guide me in the right direction?

Here is an example of the old form: http://www.cpsionline.com/golf/index.asp

Notice when you change the number of people registering that you get an alert indicating how much you owe. I could probably do without this feature, however the layout of the form is more important.

Any help you can provide/pointers in the correct direction would be appreciated.

Thanks!