Anastasia:
Check out the main resource page here on the forum, and you will find TG friendly stores located in most parts of the country. I don't know about Nashville, but I would not be surprised if there is one there. Some of their stuff may be a bit more expensive than it could be, but they are helpful.
If you go to a store that caters to post mastectomy patients, CALL AHEAD and ask them about their service. Pardon the phrase, but be up front with them and you may get service on their terms, which is usually great. Just barge in, and they will ask you to leave, or will quickly help you out the door themselves.
For under $100 you are looking at a pair of weighted foam rubber forms that have a cloth covering. They are not as nice as silicone forms, but would do for a starter pair, since they run around $60 or less. The bigger the size, the closer to $60. I have owned a pair and had many great nights out when I looked good and felt good. Silicone forms can be under $200 at places that sell non-medical forms, they are usually "seconds", but I have two sets of that kind that have given me good use for many years. You do have to be careful not to puncture the plastic cover on them.
YOU DO NOT NEED GLUE!!!! Any forms that have some weight to them will stay put nicely in a good bra. Solid, full front cups are best until you get used to them. I only use glue for VERY special outings en femme, and not all of those. I can even wear my forms in a swimming suit without glue. Make sure of the band size of the bra you are getting, and then choose a cup size you would like to be. As I said above, I look better in a C or D than a smaller size, but that's not true for everyone. Look at the GG's in your birth family, and use them as a clue to what size to use. When you have an idea, use the right band size, and the cup size of dreaming.