Kinda hard to tell... you would have to go see it in person to get a better sense of sturdiness. I've seen things look tank like but not suitable for heavy tanks but then I've seen stands look weak but be strong as an ox. In the end you really won't know until you inspect it in person.
I would bet that it is better built the the so called aquarium stands made of particle board they sell at petsmart etc. It can be easily made adequate with just a little time and lumber. What are the dimensions, can it even fit a 48" tank?