The design is great it is simple and especially practical. 
The regular price is much to high for the strength of the bed. I had to increase it strength of structure and add some feature to make it more durable .
It is a Chinese product, but it is acceptable for the price !

I added some braces and screwed all the plywood board on the frame. I added a plastic sheet to keep the dust from going inside the structure and for 
the mattress to slide better on it.  A other feature is a " J" trim on the base, to protect the paint and to be able to slide the bed more easily on the floor.