Well they have a 2008 and a 2008.5.
2 engine sizes. 3 trim levels. 2 transmission types.
But lets just say you want a basic 2008.5 Mazda 3 with all the power options, automatic transmission, but no leather or moon roof. You should pay somewhere around $17500.00
If you want a BASE BASE Mazda 3 with an automatic and a/c you will pay around $15,000