Volunteer to make the bid (5)
I believe the answer is:
offer
This clue is a triple definition!
'volunteer' is the first definition.
(I know that volunteer can be written as offer)
'to make' is the second definition.
(thesaurus)
'the bid' is the third definition.
(I've seen this before)
(Other definitions for offer that I've seen before include "Bid; proposal" , "Tender - proposal" , "Tender, make bid for" , "show" , "Expression of willingness to pay or give" .)