It is always worth it to pay a little extra for sure to reduce that compounding interest working against you. The visuals you provide are a great example of that. I haven't really taken very many loans in my life, really only one major loan I can think of, and I had a 5-year interest-free provision in mine. I was able to make it work and was able to pay off the full note in exactly the 5-year timeframe and never paid a cent of interest. In fact, to this day, I've only paid interest twice, and that was because I forgot to make my credit card payment on time -- and both times I got that sorted so I only ended up paying interest for that one month I missed.