Step 1 :First, we need to find the possible combinations of items that Dylan can buy with the given amount of money. Then, we need to calculate the total cost of each combination and find the one that is closest to the given amount without exceeding it.
Step 2 :Finally, we need to calculate the change left.
Step 3 :\(\text{Best combination:}\) Games Cap, Games t-shirt, Games Coffee Mug, and Large Teddy Bear
Step 4 :\(\text{Total cost:}\) \(\boxed{212.50}\) Australian dollars
Step 5 :\(\text{Change left:}\) \(\boxed{57.50}\) Australian dollars