The heavy duty trailers can take around 100-120 kg and can be custom made to any size, but the following are common configurations
900x600mm takes two 600 x 400mm bins, Options of angle struts between the bins. The width of this trailer makes it more difficult to squeeze through gaps. Cost $330 for frame and hitch. 24” wheels are $140 and bins are extra.
1200x600mm takes three 600 x 400mm bins, with heavy duty struts and two angle braces between the bins. Cost $420 for frame and hitch. 24” wheels are $140 and bins are extra.
1600x600mm takes four 600 x 400mm bins, made from 50x25 mm welded stainless steel with 15 mm thru axle wheels. Cost $460 for frame and hitch. Wheels are $300 and bins are extra.
Note - if you want the trailer a bit wider this will add around $20 to the price. Load space wider than 800mm is not recommended.
Custom built - you design it, I can help build it. Centre pull seat post hitches make a great hand pull cart when it’s not being towed by your bike which is very handy around the garden. This costs $120 extra as its made from stainless steel and welded.
Aluminium bins are made by a local sheet metal worker and typically cost $5-600 for a large size. You can make your own from plywood or Agpac Tuffboard (recycled plastic) which is a little heavier but likely cheaper. If you need a large bin couriered it can be made to bolt together for an extra $100 or get a local sheet metal worker to make one for you.