That was a good deal! It is your grill, do anything you want with it.
Personally, if I already had one like it that I was using I would keep that one clean until I decided to switch it out for the old one. If I was planning on camping or some kind of outing where I needed one I wouldn't hesitate to light it up! Unless it is something rare or semi-rare/NIB I think a grill should be put to use! Even then it should be tempting to use it.