A good bicycle trailer I can order
For what you are asking about I would recommend buying a used kid trailer (for about $50 - $150), cutting off the fabric and adding some kind of floor/bin.  Interestingly enough most child trailers are rated for up to 100 pounds were as the BOB trailer is only weighted for 75 (if I remember correctly).

The only advantage of a BOB or Extra wheel trailer is that they single wheel trailers.  This means they can handle faster cornering and are narrower for roads.  They also cost basically the price of a new bike.  

See here: Converting kid trailer to cargo trailer