Price and tax - tax always added

[tandem]

I have added a CA tax of 0.075 which I believe shout be the 7.75% -  I only want that to show up once the shopper has entered his address in the checkout - but I am seeing an added price - so I have the COST Price at $249
and the BASE price shows up as $249 but the FINAL price shows up as $250.8 -  how do I change this?  -  in the TAX and Calculation rules I have it set up as TAX Per Product -  and +% of 0.075  - 
Please advice