Lots of folks already online getting those Cyber Monday deals, but warnings as well from the State.  Any purchases must include sales tax.  It's the law.   Michigan Treasury Department Director of Communications Terry Stanton is warning those who buy today to keep their receipts to prove that taxes were included in the purchase price or to pay those taxes later on their tax form.  So-called 'brick and mortar" facilities--that have stores in Michigan--automatically charge the 6% sales tax, but others may or may not and it's the responsibility of the consumer to make sure the state gets its money.  .  It's estimated that the state loses upwards to 400-million dollars in tax revenue a year by those who don't pay up.