The thing I have always felt like a prick ordering is Amazon's Kitty Litter? 40lbs for $12 seems like it would be pretty good bang for your buck. I mean there may be something that would be heavier for cheaper though.

I believe this is the heaviest Prime product they ship. It isn't a good weight per $ since it costs $25,000 but it does weigh 8514lbs when shipped.

Digging around on amazon, i think this solar power kit is the heaviest if not the largest as well.

2125 lbs shipped with dimensions of 33.3 ft x 21.8 ft x 0.75 ft

edit: I lied. this monster is 8514 lbs

Finally, same day shipping on that lathe i've been wanting.