If you are in Europe, then typically you will want to enter
prices on your web site inclusive of tax. Stores
based in the US, or European stores that deal primarily with
business customers, will normally want to enter prices
exclusive of tax.
This is
controlled by the general.tax.pricesinctax config
setting which should be set to 'y' for tax inclusive prices, and 'n'
for ex-tax prices.
Note that for tax inclusive
prices, tax is calculated 'per item' rather than per row of the
basket. As such, a rounded 'ex tax' price can be calculated. But for
ex-tax pricing, tax is applied to each row of the basket.
Consequently, it is not possible to show a rounded inc-tax price for
individual items, because this would in many cases not quite tally
with the actual tax on the order (due to the different rounding
used, per-item and per-row) and would be likely to confuse customers
or lead to complaints that the site has added up the tax wrongly.
Instead a percentage figure is shown where necessary.