What's your experience with certain items that cost extreme amounts to identify?

All the usual stuff is covered when you have an Artifacts skill of 8-9, however when you're talking about The Staff of Death (Level 12 needed!) or de Soto's Divine Chain Mail, you really have to work hard at that artifacts skill.

Is it worth the trouble or should you pay 50.000+ to identify such artifacts?

Well, personally I boosted my artifact skill up to 12 - then it's possible to idendify everything. Anyway, if you equip the staff of Death, or the Chain Mail you won't suffer from any negative effects. Desoto's Mail gives some nice magic protection (20%) agains basically everything.

I can't remember the exact stats of the staff of death, but it's a powerful weapon (but a higly enchanted Wizard's blade or Robinsword will deal out more damage). The cool thing about the staff of death is that it is the ONLY weapon (except the Mavin Sword) that has any effet on Lord Cet!

Cheers // Jazzid