Thanks for doing this, to me expensive is the true way to play Factorio, but I noticed a few things.
I don't know if you are aware, but in v1.1 there were expensive recipes for Express Transport Belt (20 Iron Gear) and Tanks (double all ingredients).
Casting Steel - You made it more expensive, but not slower. The regular recipe takes twice the time.
Casting Low Density Structure - Does not account for the increased cost of steel, also the vanilla cost is 80 molten iron, not 60.
Burnt Spoilage/Carbon Fiber - You reverted your change in burnt spoilage, maybe you should have made Carbon Fiber more expensive instead.
Solid Fuel from Ammonia - They changed the recipe in v2.0.24, making it much cheaper (15 ammonia, 6 crude oil, 0.5 sec) and instead rocket fuel from ammonia required 10 solid fuel to match ratio of regular recipe.
Space Science Pack - In the playtest version and according to an FFF Space Science required U-235 (one rocket load per 1000 packs). I think it would make them a lot more interesting if you brought this back.
Also a couple of the changes to base game recipes don't activate unless Space Age mod is active (Refined Concrete, Heat Pipe, Beacon, Accumulator). Applying those changes for all of Space Age to rebalance Fulgora seems a bad idea, change the Scrap Recycling recipe instead, have it return less of compound items with increased costs.