@Meredith Jones - for benefits at the KS pricing you need to use the Kickstarter pledge tool under "My Account". You won't manage that money in the store.
Meredith, I'm a little confused. You have the Head Start as part of your kickstarter pledge already. You don't need to buy it again. You can view your rewards by going to your My Account page > scroll down to the My Pledge Drives in the right column and click on it > click on the button for "Details" for the Fantasy Sandbox MMO kickstarter and you should be able to see all your rewards. Part way through the list of rewards you will see: Adventurer Level Reward Bonus - Head Start.
Please let me know if this does not answer your question!
it was me that was confused. I get it now
(hangs head in shame (even more embarrassed that the CEO has to remind me))
Cheers - Meredith