1st of all love the idea of this mod but ... i personally don't like the idea of you actually having to go in the the area to look what you need and then going back to base to make / pick up these items and haul your ass back to “pay”
So here's a suggestion if you like it AWESOME ! if not then there's not much i can do about it :) your mod your rules.
And a note about all of this: its way longer than i anticipated hope youll like at least some of it and i hope that some itsy tiny bit might get actually realized :) all tho i have my doubts because if all of this would be actually possible to do then it would be also hell to balance and i'm not even talking about other mods integration ... so it's just a thought ... maybe some inspiration but not much else :)
Anyway here it is:
The buy process would be made via currency not items them self
this currency would be generated by “inserting” items in to building where each item value would be determined by its raw items value and little by little multiplied by its total craft time (let's say 5% of that craft time would be added as bonus value) and by static bonus for actually crafting step (3 step crafting = 3 static bonuses (idk 0,3 per craft)) so in the end the calculation of value would be something like this
Item value = (basic resource value + ( (craft time * 0,05) + (static per craft bonus * number craft operations) ) / amount of items crafted
Iron plate = (1 + ( ( 3,2 * 0,05 ) + 0,3 * 1)) / 1
Iron plate = (1 + (0,16 + 0,3)) / 1
Iron plate = (1 + 0,43) / 1
Iron plate = (1,43) / 1
Iron plate = 1,43
Note: After looking at the result i think that just total raw time bonus would be sufficient as bonus value cause it will scale quicky up as tech advances.
Currency itself would be stored as gamestat shown in GUI as “<currency name>: <money amount> ”. or alternatively visible by entering some command (/money) or worst case scenario by handling items generated inside the building where you would put the produced items for “sale” (1 full number in building = 1x currency stackable to let's say to 999 999 (hope that would fit the icon square)
Territory value would be determined primarily by resources present on that specific territory you would have to pay lets say something around 20-40% of resource value in that territory (resources density increases with distance so would be the value of territory) + static price per tile lets say 10 “money” per tile
Also all of this would be awesome if it would be configurable in settings be it percent of “pay in advance” for resource present in territory, price per tile but also value of “basic items” default: if item then value 1 if liquid then value 0,01
territory buy: ideally this would be done by interacting with some entity in game it self at least building or ideally some flying drone where you would click on it see the value it wants and have option to buy. this drone would be also what attacks you (be it the drone it self or by targeting you for orbital strike) and it targeting you with red pointer to tell player pay or get lost and with it having little countdown on top itself while pointing at you once you enter. drones would be placed in each individual chunks and then linked if you have bigger territory than 1x1 where you would pay off 1 drone but (let's say you have 3x3 chunk as territory) 9 of them would get either destroyed or optimally fly away to space
Ideally flying entity to avoid bitters and set to invincible / unattackable for the same reason
Also absolutely perfect would be if you could access this entity from map view without you physically going there assuming the currency would not be items and maybe even then... the items maybe would not be problem if you can actually open the UI of that entity from distance