For $300 or less on eBay, you could pick up a custom Halo Transformer. Just a “quick transformation turns him from the iconic Spartan soldier into a battle ready Warthog LRV.” Auction page. Click here for first picture in gallery.
Stands 5 1/4″ tall when transformed and comes with a variety of weapons including a Sniper Rifle, Spike Grenade, and Warthog turret.