What to do with money that's left in an ad campaign budget?
I'm a 3rd year Advertising student and we're currently working on a budget plan for a hypothetical ad campaign for a local business of our choice. I have no experience in making budget plans for something as big as an ad campaign and was assigned P12,000 (about 197 usd) for the budget by my prof since the business owner that I interviewed didn't bother to give me their own desired amount when I asked. The owner made it clear that if they were to pay for an ad campaign, they would like to invest more in traditional media instead of digital ads like sponsored posts and such. So I decided on working with stuff like flyers, and posters and such. After calculating everything, I still have about 5 dollars left to spend and have no idea what to do with it.
What do industry professionals usually do when a small amount of money from an ad campaign budget is still left over? May I ask for any advice on how I can defend this part in my budget to my professor? :'D Thank you..