I don't think so. As far as I know we're in the business to win trophies, not save money. When we have no FBs and when teams know that they'll charge us. Whose fault is it that we were with no FBs? Not mine. Who does the planning here, whose job is it? My job is to pay for tickets, to buy shirts, to support. Whose job is to plan, buy, sell?
A second point is, if you buy the right player today, you won't have to look for other players every year to replace him. Clubs like RM understand this very well. That's why almost every purchase they make is a world record. But they don't look for someone to replace CR7 or Modric every year. And they have the best FBs in the world. They're not in the market every year so desperately to replace them.
If we buy the best FBs available at whatever cost this year, we won't have to shop for new ones every year, we might just look for back ups but not be desperate.
We made the same mistake with centre halves and every fookin season we're breaking a new record on a new centre half to replace the one we got one year before. It's always the unproven, questionable ones that we get. With the money we spent on Otamendi + Mangala for a total of £63.84 mil and instead of still looking for a new centre half, we could've spent £65-70 mil on one of Sergio Ramos or Bonucci and we wouldn't be looking for one to replace them now because they're proven. See my logic here?
Logic should be same with FBs and everyone else.