progressively increasing cost of buying transport cap.

src/game-lib/Controller/BuyTransportCapacityPlayerAction.cs

@@ -19,7 +19,7 @@ public BuyTransportCapacityPlayerAction(ILog log, int capacity)
 
     protected override (List<int>? ids, int? targetId) ApplyImpl(GameState state)
     {
-        int buyingCost = Ruleset.AssetsRuleset.TransportCapacityBuyingCost(_capacity);
+        int buyingCost = Ruleset.AssetsRuleset.TransportCapacityBuyingCost(state.Assets.MaxTransportCapacity, _capacity);
         Contract.Assert(state.Assets.Money >= buyingCost);
         _log.Debug($"Buy transport capacity. Count: {_capacity}. Cost: {buyingCost}");
         state.Assets.Money -= buyingCost;

src/game-lib/Players/BasicAIPlayerIntellect.cs

@@ -2,14 +2,15 @@
 using UfoGameLib.Controller;
 using UfoGameLib.Lib;
 using UfoGameLib.Model;
+using UfoGameLib.Ruleset;
 using UfoGameLib.State;
 
 namespace UfoGameLib.Players;
 
 public class BasicAIPlayerIntellect : IPlayer
 {
     private const int MinimumAcceptableAgentSurvivalChance = 20; // percent
-    private const int MoneyThresholdToBuyTransportCapacity = 600;
+    private const int MoneyBufferToBuyTransportCapacity = 600;
     private readonly ILog _log;
 
     public BasicAIPlayerIntellect(ILog log)
@@ -37,14 +38,22 @@ public void PlayGameTurn(GameStatePlayerView state, GameTurnController controlle
     }
 
     private int ComputeTransportCapacityToBuy(GameStatePlayerView state)
-        => state.Assets.Money >= MoneyThresholdToBuyTransportCapacity
-           // The number of current agents has to be at least the current max transport capacity,
-           // which is still significantly below full complement.
-           // There is no point in increasing the transport capacity if we cannot even 
-           // get close to the full complement of agents.
-           && state.Assets.Agents.Count >= state.Assets.MaxTransportCapacity
+    {
+        int currentMaxCap = state.Assets.MaxTransportCapacity;
+
+        int buyingCost = AssetsRuleset.TransportCapacityBuyingCost(currentMaxCap, 1);
+
+        // The number of current agents has to be at least the current max transport capacity,
+        // which is still significantly below full complement.
+        // There is no point in increasing the transport capacity if we cannot even 
+        // get close to the full complement of agents.
+        bool moreAgentsThanCurrentMaxCap = state.Assets.Agents.Count > currentMaxCap;
+        bool enoughMoneyToBuy = state.Assets.Money >= MoneyBufferToBuyTransportCapacity + buyingCost;
+
+        return moreAgentsThanCurrentMaxCap && enoughMoneyToBuy
             ? 1
             : 0;
+    }
 
     private static bool NoMissionsAvailable(GameStatePlayerView state) => !state.MissionSites.Active.Any();
 

src/game-lib/Ruleset/AssetsRuleset.cs

@@ -1,3 +1,4 @@
+using Lib.Contracts;
 using UfoGameLib.Model;
 
 namespace UfoGameLib.Ruleset;
@@ -42,6 +43,36 @@ public static int ComputeIntelChange(Assets assets, List<Mission> successfulMiss
         return intelGathered + intelFromMissions;
     }
 
-    public static int TransportCapacityBuyingCost(int capacity)
-        => capacity * 200;
+    /// <summary>
+    /// The way this formula is set up, one gets discount for buying transport capacity in bulk.
+    ///
+    /// For example, assume:
+    ///
+    ///   maxTransportCap == InitialMaxTransportCapacity
+    /// 
+    /// Now consider:
+    ///
+    /// Scenario A:
+    /// Buy 1 price: 200 * 1 = 200
+    /// Buy 1 price: 250 * 1 = 250
+    /// Buy 1 price: 300 * 1 = 300
+    /// Buy 1 price: 350 * 1 = 350
+    /// Total: 1100 = 200 + 250 + 300 + 350
+    ///
+    /// Scenario B:
+    /// Buy 2 price: 200 * 2 = 400
+    /// Buy 2 price: 300 * 2 = 600
+    /// Total: 1000 = 400 + 600
+    ///
+    /// Scenario C:
+    /// Buy 4 price: 200 * 4 = 800
+    /// Total: 800 = 800
+    /// 
+    /// </summary>
+    public static int TransportCapacityBuyingCost(int maxTransportCap, int capacityToBuy)
+    {
+        Contract.Assert(maxTransportCap >= InitialMaxTransportCapacity);
+        Contract.Assert(capacityToBuy >= 1);
+        return (200 + (50 * (maxTransportCap - InitialMaxTransportCapacity))) * capacityToBuy;
+    }
 }

web/src/components/AssetsDataGrid/ManageTransportCapDialog.tsx

@@ -103,7 +103,12 @@ export default function ManageTransportCapDialog(
               <Label sx={getSx('Cost')}>Capacity increase cost</Label>
             </Grid>
             <Grid xs={4}>
-              <Label>{transportCapBuyingCost(1)}</Label>
+              <Label>
+                {transportCapBuyingCost(
+                  gameSession.getAssets().MaxTransportCapacity,
+                  1,
+                )}
+              </Label>
             </Grid>
             <Grid xs={12} display="flex" justifyContent="center">
               <Button

web/src/lib/codesync/ruleset.ts

@@ -23,8 +23,6 @@ export const agentHireCost = 50
 
 const agentTrainingCoefficient = 1
 
-const transportCapBuyCost = 200
-
 const skillFromEachFirstMission = [18, 15, 12, 9, 6]
 
 const skillFromEachMissionBeyondFirstMissions =
@@ -56,8 +54,15 @@ export function getSurvivalSkill(agent: Agent): number {
   )
 }
 
-export function transportCapBuyingCost(cap: number): number {
-  return cap * transportCapBuyCost
+const InitialMaxTransportCapacity = 4
+
+export function transportCapBuyingCost(
+  maxTransportCap: number,
+  capacityToBuy: number,
+): number {
+  return (
+    (200 + 50 * (maxTransportCap - InitialMaxTransportCapacity)) * capacityToBuy
+  )
 }
 
 export function canBeSentOnMission(agent: Agent): boolean {

web/src/lib/gameSession/GameSession.ts

@@ -188,7 +188,8 @@ export class GameSession {
     return (
       this.isInProgress() &&
       !this.loading &&
-      this.getAssets().Money >= transportCapBuyingCost(1)
+      this.getAssets().Money >=
+        transportCapBuyingCost(this.getAssets().MaxTransportCapacity, 1)
     )
   }