I use maltodextrin, bought by the 50# bag for about $70. Using Tailwind's 27g serving size, that works out to ~$.08/serving. Also no stomach issues going hard in the heat. Tailwind touts no benefit to protein during exercise. This is true. Adding protein during a race will not decrease your finish time. However it will preserve protein (muscle mass) for your next training or race. So I add ~15% flavored whey protein, by weight. This has worked well for me for ~20 years.

27g/bottle is a good recipe to prevent digestive issues. That's about 100 cal./bottle. However, whether or not that's adequate depends on your level of effort and the length of your ride. For example, last summer I did a hard 4-3/4 hour ride in the mountains during which I burned about 2500 calories. I replaced enough of them during the ride so that I didn't bonk, which was ~1100 calories, or 11 bottles of Tailwind. Except that I only needed to drink 3 liters during the whole ride. On long rides, I use 750 calorie food bottles and a separate plain water bottle or Camelbak.

Just things to think about.