At long last I used to be able to purchase a very similar cat tree locally at a major retailer. Like all brilliant ideas, it was discontinued.  Decent price, compact to pack away for moving, can be modifiedfortified to a point.  Sits nicely out of the way, in a corner.  Great for kittens, smaller cats or single medium cat.  Free standing and simple to assemble.  With a larger cat (and my Tom is actually a small dog or ‘big boned’ shhhh) it is recommended to rearrange shelving to put full shelves lower and secure the top like Christmas trees of yore.  Or pay double for the deluxe one.