UKH

Looking for a pair of cheap (<£100) down trousers to slip on in the tent or whilst out after dark, for an upcoming cold trip.

Any recommendations?

reason I’m going cheap is because I anticipated them getting absolutely trashed by my crampons and can’t face watching £5 clumps of goose down floating away down the mountain. 

Reccomendations/ advice welcome.

Ed 

Maybe you shouldn't wear crampons in your tent?

Depending on weight issues and how damp the camp will be, it might be looking at Primaloft trousers. They are a bit cheaper, work well in damp conditions (thinking of damp tents) but weigh a bit more than down. There are 2 pairs of cheap ones in XL on ebay at the moment.

Other option is, depending on where you live, the Mountain Equip factory sale sometimes has them on their open days.

These, perhaps: 

https://www.alpinetrek.co.uk/jack-wolfskin-atmosphere-pants-down-trousers/ 

You could try some army surplus snugpac softie trousers. Cheap and warm if a bit bulky.