Here's a little theory of mine.

(Spoilers for a bit of the last episode of Fate/Zero.)

In the epilogue of Fate/Zero, there's a telling little scene with Waver that I feel shows his moral development over the course of the series. Over supper with his host family the Mackenzies, he tells them that he's decided to start traveling and he's going to be taking a part time job to raise money for this, so can he stay at their place for somewhat longer?

There's two interesting things about this. The obvious thing is that he bothers to ask them them instead of coercing them with magic, as he did earlier in the series. However you can argue that he has no choice here because Glen Mackenzie already saw through his earlier magical coercion, but I still think that this shows a shift in his attitude towards his host family.

More interesting and less obvious is that Waver is bothering to get a part time job at all. All through the previous parts of Fate/Zero, Waver never showed any signs of worrying about money; if anything, he and Iskandar seemed to spend it freely and casually. My assumption is that Waver was using magic to deal with the problem, either to get money or to coerce people into believing that they'd been paid (probably the former since Iskandar seems to have had no problems buying things without Waver present). But now something has changed and Waver wants to get the money he needs honestly and legitimately, even if it takes more work and time.

(It seems unlikely that Iskandar was the source of Waver's money and he has no choice with Iskandar gone. We know that Iskandar was summoned in Fuyuki City, after Waver traveled all the way from England to Japan.)