I started a new game last Friday with this mod, now about 28 hours in. Noticed some items are missing marathomaton.

Engines - Normal & electric (the main reason for this post)
Angels water treatment - Structures and recipes (except sulphur purification)
Angels pressure tanks
Mk2, mk3, etc structures (this might be intentional?)

So far I'm enjoying it, works better than the other marathon mod game I had going.

you mean the items costs are not reduced, right?

Could you send your mod list?
Steam engines should definitely be more expensive -- if not this is a bug.
Not sure if electric engines would be updated.
Pretty sure angels water treatment structures are not intended to be changed.
Also pretty sure water treatment recipes should not be changed. The original marathon mod didn't really touch fluid recipes.
Similarly, I dont really see a reason to make angels pressure tanks more expensive.
Certain mk2/3 structures should be more expsnsive (boilers, engine, solar panels). Generally if the T1 structure is not affected then T2-4 will not be.

I meant engines that are used for vehicles like tanks, trains, etc. Steam engines are all good at all levels. I'll try to post more info when I get home from work today.

Engine unit/electric engine costs were not changed in the original marathon mod (maybe because they take way too obscenely long to craft already?). I'm not an expert in game balance so if you have some suggestions please share!

An Engine unit only costs 1steel, 1gear, 2*plates

A tank then costs 16engines, 50steel, 15*gear, 5 elect circuit boards

The tank mk2 is then affected by this mod, costing the tank mk1 plus 250 titanium plates, etc.

I guess its just that the engines & base tank seem disproportionate to many other items. In the same way, the pressure tank costs relatively similar resources to the other two angels tanks that are affected by the mod, but the pressure tanks hold way more gas/liquid. I don't really have a suggestion for balance either, its all personal preference I guess.

I think most Angels structures that are Mk1 are more expensive, but the Mk2+ versions are not, this includes crushers, ore sorters, electrolizers, liquifiers, etc.

Angels warehouses are more expensive, but ore silos are not.

The only item on the Angels water purifaction tab affected is the recipe for sulphuric waste water purification, the rest and all the structures are not. Actually, looking ahead, mk2 water purifiers look to be more expensive.

The Angels metallurgy tab seems to be a mix. For some structures the mk1 version is more expensive, but the mk2+ are not (eg: induction furnace). Other structures the opposite is true (eg: blast furnace)

From my mod-list.json:
base
what-is-it-used-for
bobconfig
bobinserters
boblibrary
Bottleneck
EvoGUI
no-hand-crafting
Nucular
ZRecycling
bobenemies
bobores
bobvehicleequipment
RecycleRatio050
bobtech
rso-mod
bobplates
angelsrefining
bobassembly
bobelectronics
bobgreenhouse
boblogistics
bobmining
bobpower
bobrevamp
angelsaddons-oresilos
angelsaddons-warehouses
angelspetrochem
bobmodules
bobwarfare
ScienceCostTweaker
angelsaddons-pressuretanks
angelsbioprocessing
angelsinfiniteores
angelssmelting
marathomaton

Thanks for you comments. Let me try to address as many as I can, one at a time:

• Engine unit costs 20 time in base & bob/angel -- to me, this is the main pain point of manufacturing engine units, In base 20s is far higher than anything else at that point in the game; it means that producing your first train is gated by 400 assembler-seconds. If anything I might bump up the time, since in marathon some early game materials already take 6-10 seconds.

• Tank costs are not changed in base, bob/angel, or marathon. Seems balanced since tanks are gated somewhat by tech tree but mostly by ammo production (unless you're mass producing explosives for some other reason). I might consider turning up cannon shell time/costs.

• Tank mk 2 seems to be affected by marathon mod, but is actually not. It costs 5x more titanium plates, but everything that produces titanium plates actually produces 5x more (similar to the situation in vanilla marathon with copper). If you can find a recipe that has not been 5x exploded, please raise the bug in another thread.

• Pressure tank does indeed seem to be a little OP, being cheap and easily accessible in the tech tree. However the usefulness of fluid storage seems pretty marginal to me, since storage tank already provides quite a decently sized buffer. I might consider increasing recipe cost but it'd be a very low priority task.

• Regarding supposedly-affected ore silo/angels buildings recipe changes, see above comment about tank mk2. Basically, iron, steel, and aluminium have been exploded, whereas steel has not. If you look at the raw ingredient count you will find no change there -- except for sulfur/plastic/lube/etc. which have been 0.5x'd in marathon mod.

Thanks for the discussion, these are all fair points. I'm definately enjoying the mod and will get a lot more hours into it this weekend. I don't see the raw resources display, I think because I am also using the no hand crafting mod. ;)