Agree with the others that the limited basic generation can feel a little awkwardly slow at some points, but I really think that 95% worked as intended. I really appreciated that scarcity progression pushing me into making interesting decisions, like focusing my time into upgrades to overall efficiency, vs trying to minmax the money generation to buy upgrades to the basic materials, vs speedrunning higher tier materials and hoping they would solve my problems.
If you could buy infinite of even the base materials with some fixed price like you can with other buildings, that entire carefully balanced scarcity would collapse.
Instead of getting one or two of each new building and making the most of them using your slow trickle from the previous tier, suddenly everything would center around spamming as many as you can of cisterns/quarries, then buying even more smelters, etc to use them all, and so on.
It would be a NIGHTMARE without more "flow control" type buildings like the 3 input merger, and this interface is not built to handle that much spaghetti regardless.
Also this one is definitely a nitpick but:
The upgrades tab is a bit silly containing literally just 3 one time upgrades by the end. But it's definitely the lesser of two evils, compared to trying to make the pipes a building that required upgrades or something unholy like that.
So, overall? Really really well put together and surprisingly tightly balanced for a jam game. Even if some spots end up just a bit awkwardly short, like bricks/glass and other QoL bits like zooming out, it never took away from the fun of a well made alka-like.