Unless otherwise noted, all weapon / armor enchantments require the weapon or armor already have a +1 Enhancement Bonus. So, you can have a +1<em>agile</em>Rapier, but never just an<em>agile</em>rapier. The Masterwork quality does not count for this; it's gotta have a magical +1 enhancement on it.<br/><br/>You also total the bonuses together when figuring cost; a weapon with a +1 Enhancement Bonus, and both a<em>ghost touch</em>and<em>flaming</em>enhancement is priced as a +3 weapon, not three separate +1's.