I put in a supervent chimney in January and it has been great. I went with 8 and had to use 4 sections @ $95 a section bought at medards and had a local contractor install it for $200 cash. It ended up being under $800 with installation after buying the sections and the other connectors and black pipe.
The United States of America and its agencies and instrumentalities (also referred to as United States governmental entities) are also exempt from paying New York State sales tax on their purchases. Other states of the United States and their agencies and political subdivisions do not qualify for sales tax exemption.
A VAT at the federal level would be similar to state sales taxes. States would likely strongly resist any federal attempt to usurp their sales tax authority because they rely on sales tax revenue. A VAT at the federal level would likely force states to apply their sales taxes to a uniform set of goods and services.