how I filter car quote per price min max... in other words how complex calc works

[Leonidas Savvides]

SELECT * FROM cars t1 INNER JOIN prices t2 ON t1.cat=t2.cat WHERE $priceLow < (($rate * $days)-($rate * $days)*t1.discount)*1.18 AND $priceHigh > $rate * $days;' );

$priceLow, $priceHigh from rent a car filter eg 50, 1000
$rate = "t2.h" h=stands for price for high season, t2 table db
$days = 7; eg 7 days
1.18 = vat 18%

how I filter car quote per price min max... in other words how complex calc works? is this correct?