Hi Destiny
No Taxation Without Representation! There were no colonial representatives in Parliament, and colonists believed that only their colonial legislatures had the authority to tax them.
The tea was so cheap even with the tax, so some colonists were afraid that Americans would buy British tea rather than the tea that Americans smuggled in from other countries. They wanted to support American merchants, even though smuggling was illegal. Buying tea from the British would hurt the American boycott of British products.
I hope this helps out a bit.