1. Land expansion items, like the storage ones, are extremely rare. The more you level up, the more difficult to find they become.
That’s because every new level unlocks new items, therefore lowering the statistic probability to see rare items for sale on the Global Market. You should take the opportunity to collect these items early in the game, when they're relatively easy to find.
2. Storage management - which may be considered the main challenge of this game - becomes progressively more difficult as you level up.
Land expansion items take space in your inventory: unlocking the most expensive pieces of Land can require up to 60 items. Imagine having to keep in your inventory 75+ storage items, 60+ land expansion items, 60+ Vu items for CoM, a bunch of War Items AND a reasonable stock of every single hard to found item you have the ability to produce... That’s obviously easier to do when you have just a few items unlocked.
3. When you unlock the last piece of land in your Capital’s Map, you won't receive the dreaded "Expand City Area“ task anymore.
“Expand City Area” is one of the most hated CoM assignements ever: insanely expensive, incredibly pestering (when completed, it usually comes back in a couple of rounds), and always worth 2000 points, which is not such a good score considering how difficult to complete the task is. With a fully expanded Capital Map, you won't see the ”Expand City Area” task in your list ever again.