I have a trailer that weighs probably 300lb unloaded and I can easily pull it by hand even in the dirt and on a slight incline. It utilizes large truck tires and a large truck axle. I could probably slim down the tires/rims and axle and move it a lot easier too. I've loaded it down with firewood for 3 nights, camping gear w/food and water for 3 nights for 4 people, etc... and that was only up to the VERY LOW edge probably 1.5' or 2' tall. Double that if I add supports, and the trailer still is reasonably light to move by hand and holds enough gear to live out of for 3+ days. That thing doesn't even come with water! Pills, and an empty container that's no good

I've moved 1500lb jetski trailers by hand w/jetskis on them the smaller tires really make it much easier, and two of us have pushed it up a rather steep driveway...

I think you could make your own setup MUCH better for the same pric and then add your own gear you mostl ikely already have