Land expansión and lack of Dozer parts! Help please!

Create a brand new GameCentre/Google Play/Facebook account
Use this new account to start a brand new city.
Spend 30-45 minutes playing through the tutorial then getting your new city up to level 8/9 and a 10,000+ population.
Hit the GTHQ. Because of your low level all you'll see is storage capacity items, metal, plastic, wood and land expansion items.
Buy all the dozen blades you need then sell them to your main city.

I speak from personal experience when I say it works a treat.