Fix issue of nowhere to buy a material (mainly for mineables)

app/star_citizen.py

@@ -238,15 +238,16 @@ async def calculate_trade_profies(commodity, scu=None):
                 costs[station] = trades["buy"][commodity] * int(scu)
                 break
 
-    embed.add_field(
-        name="**Best place to buy %s of %s**" % (scu_string, commodity),
-        value="%s: $%s"
-        % (
-            min(costs, key=costs.get),
-            "{:20,.2f}".format(costs[min(costs, key=costs.get)]).strip(),
-        ),
-        inline=True,
-    )
+    if len(costs):
+        embed.add_field(
+            name="**Best place to buy %s of %s**" % (scu_string, commodity),
+            value="%s: $%s"
+            % (
+                min(costs, key=costs.get),
+                "{:20,.2f}".format(costs[min(costs, key=costs.get)]).strip(),
+            ),
+            inline=True,
+        )
 
     # Same logic, but finding the place buying the commodity for the most
     profits = {}