There is a presharpened carbalt graver on the website sharpened to a 116 universal point.
Here is a link to add one to your shopping cart As long as you stay in something like copper for practice you should get away for quite a while before re-sharpening would be needed. Like Tom said though, particularly when just learning points break often in steels. Copper would be more forgiving that way.
To touch (resharpen) this graver back up you'd just need the first item listed on this page link for $89 and a 2000 diamond bench stone $39
Also there are manual push sets on the site. To find them click here:
http://www.airgraver.com/Hand_Engrav...s_Overview.htm
and at the menu at the top of the page click "Manual Operated Engraving Tools".