Unexpectedly bid a lot for a popular newspaper (7)
I believe the answer is:
tabloid
'a popular newspaper' is the definition.
(I've seen this before)
'unexpectedly bid a lot' is the wordplay.
'unexpectedly' indicates an anagram.
'bid'+'a'+'lot'='bidalot'
'bidalot' with letters rearranged gives 'TABLOID'.
'for' is the link.
(Other definitions for tabloid that I've seen before include "Popular style of newspaper, not broadsheet" , "Smaller-sized newspaper" , "Cheap newspaper" , "Type of newspaper" , "daily, perhaps" .)