Free to pay for facilities on top of Everest (9)
I believe the answer is:
footloose
'free' is the definition.
(I've seen this before)
'pay for facilities on top of everest' is the wordplay.
'pay for' becomes 'foot' (as in to foot the bill).
'facilities' becomes 'loos' (loo is a kind of facility).
'on top of' says to take the initial letters.
The initial letter of 'everest' is 'e'.
'foot'+'loos'+'e'='FOOTLOOSE'
'to' is the link.
(Other definitions for footloose that I've seen before include "without responsibility?" , "Eager to travel" , "Able to travel freely and do as one pleases" , "Able to go" , "Fancy-free" .)