I am not sure I understand what you want, but it sounds very simple:
$dbquery = "select color, size, price, material, ref, style, condition from table where ($item = '$ID)";
(considering ID will always be the same like you say!)
your link should be
<a href="http://www.domain.com/script?item=1" target="_self">Item1</a>
or
<a href="<?php echo "$PHP_SELF".'?item='."$item"; ?>" target="_self"><?php echo $item; ?></a>
Good luck,
Luciano ES
Santos, SP - Brasil