Utd can afford to spend big again next season if they miss out on the CL and they only did this year because they missed out. While Utd were consistently making the top 4 there was no reason for the Glazers to allow big money to be spent.
Utd will keep spending to get back into the CL because the tv money, increased exposure etc is worth more than what they'll spend. The challenge will be keeping and attracting players like Di Maria.
You should know that you can't always just look at results when comparing the 2.
Moyes wasn't just getting poor results but there was little to no positives to take from anything at Utd and you couldn't see what he was building towards. Utd were drifting towards mediocrity. It's still early and a lot has gone wrong but Utd appear to have more about them now than under Moyes. You've got to give it a few more months before you can begin to judge LvG though.
It was no different to people comparing Benitez's first season to Houllier's last or the morons comparing Rodgers to Hodgson in his first season too. In Benitez's and Rodgers' first seasons the results weren't always there but you could see the club was moving forward and something was being built. Even if Utd don't break back into the top 4 this season you can't simply judge LvG on that. It's about how things happen and what are the indications on how things will progress.
Of course they weren't building towards anything, they went out and panic bought him Fellaini at the end after failing to get anyone else. (Or felt the team didn't need more players).
That said it isn't really Moyes or LVG fault the club ended in this situation they've had to ***** loads, its fergusons