If you click on one of the ui categories that menu should stay open for you, as opposed to hovering from it over to what you want to build each time
Seems i'm nearing the end myself looking at your factory (which is a mental thing)
Prices of machines was actually a really nice and realistic change- like in real life when you have the production line up and 'research cost' is somewhat eliminated, things become cheaper to make and get more of
So yeah it was nice to see things getting cheaper as you need more of them (dozens and dozens of storage crates)