I have used items at the 99 cent store. a bbq brush, wooden spoon, clothespins, clotheslines, etc. Big 5 or another sporting good store is a good place to buy paddles. sporting paddles are usually 2 for $6.

Tack store for riding crops usually are $5 and up. you can also buy a whip there, but i agree with the advice above. get training before you use a whip.

And if all else fails, visit the local thrift store.
Tim