Mine is jeffed and I'm somewhat baffled by the range of potential replacements.
What am I looking for in a headset? How much should I be paying for a half decent XC friendly one?

i've got a cane creek s3 which if you can get for twenty odd quid is a bargain. sealed bearings. bargain. Lot of people swear by chris kings but i think a hope is much better value and will last you ages and ages.

Rubbish, chris king is the only headset.

Can get 2nd hand ones off ebay for less then £60.

chris king are the best. no rational man would deny that.

current Hope headsets are great.. once fitted never had to fettle with them. (they used to make a rubbish Hope Enduro headset, but since they ditched that design they have been brilliant)

CK are very good too.. look great for bike tarts (like me)

Crane Creek make some brilliant ones too, their top end ones are IMO equal to CK and possibly better. brilliantly sealed.

whatever headset you get, make sure the bearings and races are stainless steel (or ceramic if you have loads of spare dosh) – since it's the small amount of damp that gets in paset the seals and causes rusting that kills the bearings.

I also went for a hope headset as a replacement – 7 months now and no probs – I have has cheaper ones before but ahev gone in 1 year – Yes I did routinely strip them out!

ive had chris king's on both my bikes for over 13 years now… both still running sweet…. got to be a bargain 😛

Upwards of 25 notes should get a decent boggo sealed headset from the likes of Cane Creek or FSA. Should last a couple of years at least if you clean it out and grease it regularly. 30-60 notes will get a better sealed better finished version of the standard ones. £90+ should be a fit and forget piece of bike jewellery.