What to wear in cosplay~ "Tifa Lockheart"?

guys i need your help~ we're going to have a cosplay in my school but until now i dont have a costume to wear~ im thinking of wearing "Tifa lockheart" bec. they told me that i look like her~ but my problem is that i dont have time to buy my costume and im sure its expensive~ so~ is there any idea for that? it must be cheaper...