In the build/upgrade menu, it would be useful with a button to specifically put an item in the queue.
For example, I want to buy the Hazmat Suit BEFORE buying the Excavation Rig, but I can afford the Excavation Rig but not the hazmat suit.
So I can queue up the hazmat, but I can NOT queue up the Excavation Rig, only buy it right now.
But if I buy the Excavator, then the area becomes full of barrels that I can't process before getting the hazmat, so I can't get any resources from that area if I buy them in the wrong order.