Yep, $100's a steal.
A 30" bb' is usually much too long for hunting in close/brushy areas, for two reasons:
1)Most are choked too tightly (full choke), meaning the shot must be spot-on to hit, but all those pellets will make meat inedible.
2) The longer bbl usually will get hung up in branches. etc, if/when a sudden game shot is presented.
The 30" bbl, however is preferred for when the gun must be swung steadily, as when shooting long range (where the shot pattern will have a chance to open before impacting game), shooting Sporting Clays and/or Trap (where you want as many pellets on the clay pigeon as possible to break it).
Those Mossbergs used to be sold as Combo's - a 28" bbl and a 18" or 20" deer barrel with rifle-type sights.
If you want to hunt deer, I would suggest buying a deer barrel w/sights to use deer slugs, OR
get a screw-on side-mount scope mount, a 2x shotgun scope (for good eye relief), sight it in and dance with who brung ya.