Best Chews?

Beyond the need for most people to consume 150-300 calories per hour during the bike and 100-250 per hour during the run, fueling is an individual thing.

Pretty much any source that's mostly easily digested carbohydrates will work.  You don't need to use products like Gatorade, Powerbar, Hammer, Infinit, etc.  Many people use whole foods like bananas, homemade rice balls, potatoes, or other processed foods like fig newtons.

BUT, most people should start by training with whatever is going to be available on the course on race day to see if that works for them.  Living off the course should be your first choice, and carrying all your own fuel the second option.

I make a lot of my own food for rides while I'm training, like this for example:

https://www.youtube.com/watch?v=Bslh-cJnGzs

Also good are small red potatoes - you can cook those, put them in a ziplock with a little salt and they're basically pure starch.

And finally, you can buy bulk maltodextrin for your own drinks if you're just trying to save money.

If you want inexpensive like Don and others have said, anything that is carbs that are easy to digest can work. Avoid products with fat as that effects digestion time. Products like gummy worms/bears are cheap and easy to digest. Plus you can figure out how many you need to eat per hour to get enough calories. They aren't on the course but they fit other perimeters you have brought up. Go to the candy aisle, pick out what you like that is easy to eat while cycling/running, that doesn't stick and get messy, has no or very little fat and give it a go. You could buy them in the smaller packages like for Halloween so they are prepacked and you may eat x number an hour. I used to buy starbursts for my IM training and racing.