My number one recommendation for where to buy tea, about twenty minutes from UTD, is The Cultured Cup. They have a huge selection of teas to choose from and informed staff who can help you pick out which tea to get. There aren't many tea shops around Dallas, so it's nice having at least one great place where you can go see and smell teas in person. Every Saturday they also do free tea tasting events from about 10:30 to 4:30 so people can come by and try a few interesting teas without spending any money. It's a lovely shop and I've gotten lots of teas from them that are all excellent quality. Ordering from their website is also great because they have really nice detailed descriptions for every tea they sell and it makes it easy to figure out which one sounds good to you.