These are professional quality shelves.  I have seen the exact same type of shelves used to hold buspans and clean dishes when I was a dishwasher, and to hold dry stock weighing hundreds of pounds.  And, when fully assembled, they are quite stable without all the added braces needed for the junk-mart shelves these are replacing.  (Which also totally rusted out.)  And assembly was quite easy, requiring no tools aside the supplied wrench (which wasn't even needed), unlike the junk mart unit that required tools and took even longer to put together.

Granted, the price is a bit on the steep side.  However, for professional quality, it is well worth knowing I will not be having this unit buckle because the shelves bent (as did the junk mart unit), crack (as many plastic units do), or rust out in a few years with only 100 pounds of load.  Definitely, I recommend spending the extra money and getting this, or a similar unit in another size if this is not the right size for your needs.