Price +4,000 gp
Aura moderate illusion; CL 10th; Weight —
A glamered weapon can be commanded to change its shape and appearance to assume the form of another object of similar size. The weapon retains all its properties (including weight) when so disguised but does not radiate magic. Only true seeing or similar magic reveals the true nature of a glamered weapon while it is disguised. After a glamered weapon is used to attack, this special ability is suppressed for 1 minute.
Craft Magic Arms and Armor, disguise self, magic aura; Cost +2,000 gp
You can use a regular crowbar, and once you can afford that get a real weapon. I would not try to keep the improved weapon thing after a certain level. Once you fight certain creatures something like this just seems quaint... also get a backup alchemical silver and cold iron crowbar^^