If you are just wanting to twonk a bit of metal, then get to a scrapyard and find a truck disc or drum, I went for a disc (ex Citaro bus) as it provides a lump of thik steel around the edge to hammer onto.
Then make friends with your local railway depot and you are almost there, some coal, a hairdryer, a hammer and you are away.
All of above was free, so for $50 you should be laughing.