What are some vegan thickeners for beverages? I need a vegan thickener that dissolves well and doesn't have any flavor. I tried tapioca flour the other day and it didn't dissolve very well and left a powdery mouthfeel. Cornstach is not bad. Arrowroot seems to work like cornstarch but it seems like you need more arrowroot to do the same job as cornstarch.

I'm specifically looking for answers involving personal experience with hot and cold beverages - not a list of thickeners I can find online. Hot chocolate and chai are two drinks that I've been doing with non-dairy milk but I would like a creamier, thicker mouthfeel like you'd get from whole milk or cream. 

I'm aware of xanthan gum, agar agar and carrageenan, but they're all relatively expensive so I have not personally tried any of them. Personal experience with those would be cool. I really like this Bolthouse Farms cold chai protein drink, which is vegan and lists carrageenan as an ingredient, so I was thinking about trying to get some of that. Also guar gum? Cellulose gum?
Xanthan gum may be more expensive than you like, but consider that you so VERY LITTLE of it that it will last a long, long time. There's a reason why it's used in industrial production so much, I think -- it's very cost effective.