I sell fireworks and am familiar with fireworks in the industry, and TNT fireworks are some of the most expensive around. They use all kinds of fireworks coupons and “deals” to try and lure you in but their prices are higher than anyone else’s. Here’s a couple of examples.
Buy one get one Free item that costs $2.00 for one and you get the second free. A second fireworks company sells the exact same item for $.25 each. That means two cost $.50 instead of $2 at the other store.
A family pack at TNT costs around $60 and at another stand it costs $35 dollars. So, throwing in free items for them is easy because they are making so much more on items.
TMT may have decent fireworks, but take their ads and coupons with a grain of salt because they really aren’t that good, and in the long run, you might pay more. Shop around and see.

I buy all my fireworks on July 5th. Most stores have them for half price, buy one get one free, or better. Then, the next year, I don’t remember what I bought, so I get a nice surprise.