Then don't.
This game is about changing your city and adapting to the needs before you. If you need more space for the Amuni, then either grab all the free expansions you can or sell some buildings.
It's about the hard choices.
I only started a little under 8 months ago so I'm not there yet, but I almost died laughing when a fellow told me that the first expansion in the new row costs 9,000 diamonds. That's the cost of two new AAA games for just the
first of the
12 new expansions!
Seems to me that the hard choice is increasingly becoming one of three options: cough-up, delete half your buildings or quit. As you reach the final chapters there just isn't the space to play the game properly unless you're willing to divert a few mortage/rent payments to a little browser game instead.
I'm sure that Inno know their market and make more money by targeting the whales than us common folk. I'd happily pay 10 pounds a month to eventually 'unlock the full game,' but I can see that this small amount wouldn't even begin to scratch the surface as things stand in this game, so I've paid nothing more since my first and only diamond purchase. Alas, it's simple numbers though - if, for every person that's willing to pay 1,000 of their currency to unlock the full game, there'd only be four people willing to pay 200 to do the same, well, the numbers say ignore those four people and focus on the one instead. Inno need money to pay their staff and cover their other expenses and of course they also need to deliver a return on investment and so they're duty-bound to do whatever is best for the bottom line, fair enough. The danger is, however, that the frustration of the many eventually boils over and soon you only have the few whales left and then they might get bored when their less well-off (or, if you prefer, more savvy) friends have gone and thus not stick around much longer themselves either. It's a tough balancing act, I just hope that Inno can get it right. However, from the sheer number of complaints I've been seeing, I'm a bit worried that people in the later chapters really are being space-squeezed a bit too much and are starting to resent it.
Ah, just realised that made a mistake above when I said there were three options, I forgot about the fourth option, 'play creatively!' That is to say, create dozens of alternate accounts to pump KP into your space-saving ancient wonders. My sense of ethics and fair-play won't let me do it, but if anyone reading this was sheltered from these pesky concepts in their formative years, knock yourselves out! - I'm told that it is a perfectly fine way to play the game.