made tech vendors button a tad smarter.

src/Locations/ui/RamButton.tsx

@@ -0,0 +1,49 @@
+import React, { useState } from "react";
+
+import { Location }                     from "../Location";
+import { createPurchaseServerPopup,
+         createUpgradeHomeCoresPopup,
+         purchaseTorRouter }            from "../LocationsHelpers";
+
+import { CONSTANTS }                    from "../../Constants";
+import { IPlayer }                      from "../../PersonObjects/IPlayer";
+import { purchaseRamForHomeComputer }   from "../../Server/ServerPurchases";
+
+import { StdButtonPurchased }           from "../../ui/React/StdButtonPurchased";
+import { StdButton }                    from "../../ui/React/StdButton";
+import { Money }                        from "../../ui/React/Money";
+
+type IProps = {
+    p: IPlayer;
+}
+
+export function RamButton(props: IProps): React.ReactElement {
+    const setRerender = useState(false)[1];
+    function rerender(): void {
+        setRerender(old => !old);
+    }
+
+    const btnStyle = { display: "block" };
+
+    const homeComputer = props.p.getHomeComputer();
+    if(homeComputer.maxRam >= CONSTANTS.HomeComputerMaxRam) {
+        return (<StdButtonPurchased
+            style={btnStyle}
+            text={"Upgrade 'home' RAM - MAX"}
+        />);
+    }
+
+    const cost = props.p.getUpgradeHomeRamCost();
+
+    function buy(): void {
+        purchaseRamForHomeComputer(props.p);
+        rerender();
+    }
+
+    return (<StdButton
+        disabled={!props.p.canAfford(cost)}
+        onClick={buy}
+        style={btnStyle}
+        text={<>Upgrade 'home' RAM ({homeComputer.maxRam}GB -&gt; {homeComputer.maxRam*2}GB) - {Money(cost)}</>}
+    />);
+}