For an obvious beginner with form or shooting problems, just go down to any place that sells arrows and buy the cheapest arrows you can get. I don't mean the little wooden oneswith the pressed on field tips, but a lower end arrow that's reasonably straight. When he gets better you can upgrade. Heck, here's a link to some aluminum arrows at Cabelas for $40 for a dozen. A shop would sell you the same quality in a half dozen and you're out only $20.
http://www.cabelas.com/cabelas/en/templates/pod/horizontal-pod.jsp?_DARGS=/cabelas/en/common/catalog/pod-link.jsp_A&_DAV=MainCatcat21424-cat600285&rid=&indexId=cat600285&navAc tion=push&masterpathid=&navCount=1&par entType=index&parentId=cat600285&id=003320 8