I picked up some toys for my conditioning days this week. Two kegs, filled with sand weighing in at 153 and 207 lbs (measuring is hard). I made a little loading platform out of my sawhorses and a giant cutting board that I inherited (it broke already, unfortunately). All in all, the setup cost me $67 for the two kegs (letgo) sand (have a 60 lb bag in my shed still) and the two pipe caps. I did timed loaded carries yesterday before my sled work and I'm legitimately surprised at how hard the 207 lb is compared to the 153. The 153 I can get up to my chest and basically sprint with it. The 207 is a bear and I'm lucky to get a power walk. I had my wife time me on my 4th set and I clocked in at just under 24 seconds to pick, carry and load both over a 50' distance.
Edit: Apologies for the state of my yard. I have 200 lbs of dog, and keeping a nice lawn is impossible. What doesn't get torn up gets pissed on until it's dead, and then it gets torn up anyway.