Yes! However, you need to be a little lucky when killing them. You are going to get a loot of 80k per kill on average. A lot of that is in the crystals you might get. You have a 1 in 128 chance of getting any crystal and a one in 512 chance of getting a specific one. The primordial crystal is worth almost half of the value of the average kill value of Cerberus. The crystal is worth 22 million GP, but it has a drop rate of one in 512. So you will need to keep killing Cerberus to have the crystal and make a real decent profit here. However, if you are not doing it for profit, and you are more interested in getting supplies for your ironman, you will get a lot of interesting drops here. You can get runite ore, interesting seeds, and even ores. So you can get materials for all the resource-heavy skills while killing him. Moreover, if you are an ironman, you will need to kill Cerberus if you want the best in slot boots for ranging, melee, and magic. You will need the primordial crystal for primordial boots, pegasian crystal for pegasian boots, and the eternal crystal for the eternal boots.