There are two places to camp for coffer keys in Crawler's Nest:
1) From the Worker Crawler pit, go SSW and down the tunnel to the map with the big square room and the secret room. Head through the big room (with sneak and inivs) and take the tunnel in G-9 past the Rumble Crawlers. Camp in the corner in F-9 and pull Helm Beetles, Crawler Hunters and Knight Crawlers.
2) From the Worker Crawler pit, go NW and down the tunnel to the map where parties seldom go. Sneak up and head north past the Doom Scorpion and Soldier Crawlers to a room with Labyrinth Lizards (aggro sound). Continue north through a tunnel with Witch Hazels (not aggro) to another room with Labyrinth Lizards. From here, head west to a room with Rumble Crawlers. Continue west and camp in/near a room with Crawler Hunters. Further west is a room with Knight Crawlers. There are no Helm Beetles on this map.
Both of these are decent places to level in your early-mid 50s; the second is somewhat tougher, both because there aren't any beetles and because there isn't really a safe camp, but I had a good exp party there at 54.
Edited, Tue Sep 7 14:05:32 2004