Charge for Gumpaste and Modeling Work?? How much?

A client just sent me a picture of something they are interested in.  It's a cake from a place called Lady Wrights Delights.  I am just starting out and have a pricing matrix to cover my costs for buttercream and fondant cakes and basic gum paste work, but there are a lot of things I haven't actually done before, so i don't actually know how long it will take me to do them.  Also, because I haven't done them before, it might take me longer and feel like passing on that cost to the consumer can only go so far.  I was just curious what other people would charge for the additional items on this cake (not the cake itself) including the helmet which I would do out of RKT.  I was thinking that the balls and the whistle would be like $3-5 each, and the tees just a couple bucks.  The golf club though $10-15?  Computer $20?  Football $15-20?  Helmet, no idea?  Too much, too little?  Thanks for your insight.

Thanks for all the suggestions.  Get this, I quoted her around 500, but told her that it would still depend on the exact details she wanted, etc.  She was astounded at the price because apparently, she didn't know that all that stuff in the picture was made out of sugar, fondant, etc.  She thought it was all real.  She said she would just buy the stuff to put around it and just needed the cake, but that she didn't want any fondant and the cake probably wouldn't be eaten anyway since it was just a centerpiece.  Why would you want to spend money on a cake you won't eat?  Just buy a pedestal or something.  Also, if you aren't eating it, what does it matter if you don't like the taste of fondant and P.S. there is fondant all over that cake.  It's just funny because she sent of picture of what she wanted and it ends up, she doesn't want anything that is actually on the cake.