Mall Scavenger Hunt Ideas?

For my birthday party, I want to have a SCAVENGER HUNT at the mall. I am splitting my friends and I into two groups. Each team will get a specific ammount of money to spend in the hunt. There will also be a time limit. Then, there’s three categories for the hunt. They are: things to buy, things to get (as in freebees) and things to take pictures of. Any suggestions of what to put in the categories? Also, what would be a good time limit for 7-8 teenage girls?

10pts best answer!!!