420 000 is for a solo elf. Therefore, 62 000 per a non-elf of a party of six matches the value above.
"Dark Dawn" and "Job's News" are weapons. "Dark Dawn" is a dagger, which inflicts 20-74 points of damage and, moreover, it casts Sleep. "Job's News" is a main gauche, which is a bit worse but it is still a usable weapon. We also have "Sting", which is better than Job's News and, moreover, it is poisonous and death striking but only some characters can use it
When a monster sees these weapons then it can guess what will follow. And it will be correct with its guessing. In the other words, the weapons are self-explaining
Back to Leprechaun. In my current experience, you'd better attack the sucker with well enchanted melee weapons. Get rid of the ctrl nuisance somehow and then attack with weapons from behind. Make sure you are attacking from behind all the time, this will prevent the sucker to teleport you away. Well, the sucker can still teleport himself away. You can prevent it if you are enough fast with your weapons.