I'd only keep the map if it's really great (short distance to tristram and short distance to king). Else, keep doing the multi games. Before long, you'll have one of each unique he can drop (even war staff, great axe, etc). When he then tries to drop those uniques again, he'll fail, produce a 5x dura rare, and try up to four more times, resulting in 5 rares every 3-4 runs. Which can produce a LOT of rare plated belts, pikes, light plates, bone helms, greaves and the like. You should be able to get close to end game gear this way.
If you do find a great map, and the king regularly produces a pattern which goes something like "pike pike ring plated belt greaves", then by all means, run that map dry. Probably the most effective way of farming SoJs too.
If you do find a great map, and the king regularly produces a pattern which goes something like "pike pike ring plated belt greaves", then by all means, run that map dry. Probably the most effective way of farming SoJs too.