Again, with school starting up again soon, most states offer a weekend in August each year where you won't be charged for sales tax on certain items.
GUESS WHAT??? Maryland is ACTUALLY participating this year! I'm so excited!! MD has never participated before, that I can remember, and we actually get a full week. Through the week of August 8th (remember, my birthday, and what an awesome present!!) to August 14th, any article of clothing or footwear under $100 will be tax-free (this discount is not applicable to accessories such as jewelery or handbags). So, yes, an article of clothing that is $99.99 will be tax-free.
Here is the full list of states that will be participating. Check out the link your state provides to see any specifications. Most states have the same max cost of items that Maryland does, but some also have additional savings on things like school supplies.