no idea how much a sandbag costs. an easy way to know what exercise is good for, look at the pro athletes in that area. in your case, look at the pro boxers and see if you like how their body looks like. imo, boxing is a more conditioning exercise rather than muscle building. sure, you'll build muscle, but dont expect to gain alot of muscle. and btw, this is the BB section, you should be posting at the health & fitness section, you'll probably get more replies there.