Dont break after rewarding first job. Just in case...

com/gamingmesh/jobs/Jobs.java

@@ -1002,7 +1002,6 @@ public class Jobs extends JavaPlugin {
 
 		if (prog.addExperience(expAmount))
 		    pManager.performLevelUp(jPlayer, prog.getJob(), oldLevel);
-		break;
 	    }
 	}
     }

shopItems.yml

@@ -25,6 +25,8 @@ Items:
     RequiredJobLevels:
     - Miner-50
     - Woodcutter-10
+    # (Optional) Total level from all jobs player currently in
+    RequiredTotalLevels: 100
     # (Optional) Performs comands on item purchase
     # use 'msg ' at start of command to send nice message to player
     # all other commands will be performed normaly as they would be executed from console