In January, money is not usually the answer. The first priority is to keep 'our' players; second, keep the loan players, if possible. Then it is a matter of recruiting, if Wilder wants, some of the following: Young players from higher leagues, on loan; players in last 6 months of contracts who can be bought relatively cheaply; good players from the league below, or from clubs in our league who have financial problems. We are unlikely to be able to buy good players from higher leagues, or from clubs in our league unless they have money problems. Good as it would to acquire a good player to cover for Duffy, it is hard to see where you would find a similar player willing to sit on the bench.
For me, the number one requirement is for the Board to trust Wilder's judgement, and if he feels a player will improve our promotion prospects, they should look at his record so far, and back him up.