Perhaps Melo isn't the guy we need to win CL but we're not competing in europe next season. If you get ten pennys and your roof is leaking and fixing it costs 7 pennys you don't spend those 7 pennys on the roof and 3 pennys on changing your front door which is still working.
I'm not saying we should be cheap but we don't have to spend every euro we have. Fix the obvious problems and get maybe on or two quality players (Aguero and a left winger). Get a team ready to compete for at least top three and after next season start all over but focus even further on bringing quality. Melo isn't our biggest problem, we don't have any left winger and we could use one really good striker up front. I don't even consider Motta as an even avarage fullback in serie-a but focus on taking on problems one by one.