Be sure to check out the city market.

You will be able to build it after reaching level 13. The building costs 110,000 coins. The construction time is 18 hours. You need 70 infrastructure points to purchase it.

At the market you will be able to buy missing items and materials. The offers at the market are updated every 6 hours, but the timer can be speed up for Megabucks. In addition, you can reduce the waiting time by 2 times by applying the "Dynamic Market" circuit in the Lab. The layout is active for 3 days.