Features are worth paying extra for when they solve a specific problem for your cat or make the tree easier to maintain. Examples include a genuinely roomier sleeping platform, a layout your cat can navigate comfortably, removable covers and replacement components that are actually available for the model. A useful scratching section should be positioned so it can be approached and used, rather than hidden behind another platform.
Consider the quality of the documented construction and connections rather than assuming more accessories mean better value. Decorative details may suit your home, but should not take space away from the areas your cat needs. Think about the next few years of cleaning and wear as well as the first photograph. Paying more is worthwhile when the additional benefit is clear and relevant.
For scratching, the usable uninterrupted section matters more than a decorative total post height. Cats Protection recommends a stable scratching surface that lets the cat stretch fully; a platform crossing the post can interrupt that movement.
For product comparisons alongside this advice, see Ultimate PawHouse and Taj-MeowHall. The details below explain their sizes and uses.
Further reading: rspca.org.uk.
Ultimate PawHouse
Taj-MeowHall
Cat-Cave