If I were looking to buy a bottle tree, I'd probably get this instead. I have a red bottle tree and it takes up space and only holds 45 bottles. An inconvenient number since a 5 gallon batch is ~52 12oz bottles.
My bottle tree is expandable; just unscrew the top hub/handle and screw on another "wheel" of nine drying "branches". When I got it, it had five wheels that could hold 45 bottles; I added another to get to 54 to handle a 5 gallon batch.
I've been wanting to do that, but can't find single "layers" for sale. Do you know where to get them?
I got mine from my LHBS (where I bought the original tree) here in SE Michigan a couple of years ago. Seems to me it was only a few of bucks for the additional piece.
Here's an example - not exactly like mine, but same idea: