Are there any taxes/aditional costs applied in the USA when purchasing a digital slr camera within the USA?

I know there is a tax when buying within the state of NY, but I don't know about the other states. I have heard some people saying that there is a 6-10% tax no matter what state. Is this true?

A company MUST charge you sales tax if you order from within the state it is located. All other states, they do not charge you sales tax. However, most (if not all) states require you to report the purchase (yeah right) on your state income tax and pay their state's sales tax on the item.

state sales tax.

State Sales Tax - depending on where you are and where you are buying from:
Example: If you are in Detroit, MI and you buy locally from a store in the state of Michigan, then an additional 6% Sales Tax is added. If however, you are in Detroit, MI and you buy from a store in any other state via the internet or via mail order then no sales tax is applicable. Sales tax is only applicable when making a sale in a given state when you are present in that state at the time of purchase.