An awful lot of money for a boat (6)
I believe the answer is:
packet
This clue is a double definition.
'an awful lot of money' is the first definition.
(I've seen this before)
'boat' is the second definition.
(packet is a kind of boat)
'for a' acts as a link.
(Other definitions for packet that I've seen before include "bomb" , "Mailboat; item of mail" , "Paper or cardboard container" , "Paper/cardboard container" , "A boat; large sum of money" .)