This could be a great project to work on, for vending machines are genuinely useful. However, it's less satisfying to do when you know someone else has already done a neat job, like this one here:
I'm impressed by the model above for its simplicity, neatness and accessibility. The huge model below is also impressive, but less neat and less accessible for you would need a huge Lego parts collection and many non-Lego pieces to create it:
So, should I try to make a vending machine of my own, or should I try to think of something that hasn't been done before??