Old-fashioned advice is to take them in exchange for money or goods (6)
I believe the answer is:
Here is my best explanation:
'exchange for money or goods' is the definition.
'old-fashioned advice is to take them' is the wordplay.
'old fashioned advice' becomes 'rede' (rede is an archaic word for advice).
'is to take' means one lot of letters go next to another.
'them' becomes 'em'.
'in' is the link.