The England international cost his new employers more than £50m, but he says that those sorts of figures do not bother him.
In an interview with 'Sky Sports News' the 27-year-old said: "It's out of my hands. Whatever the two clubs decided to pay, that's nothing to do with me."
"I've just got to concentrate on what got me here - keep playing the football I was playing at Tottenham, keep wanting to learn, keep being enthusiastic and showing the desire on the field to go and win trophies, which is what I've come here for."
In a quirky twist of fate, Walker will line-up against his former team-mates on July 29, when City and Spurs face-off in a friendly.
"It's typical," said Walker. "When I went to Aston Villa on loan from Tottenham my first game was against [former club] Sheffield United. Football's a strange game and you never know what's around the corner."
"It'll be good to see them. It's good that we're playing in a neutral ground where it takes a little bit of the spice off it, then come the season it's business-time and I'm just trying to get the three points."