The Aussie midfielder, who hinted that Everton may yet add to their squad, paid tribute to chairman Bill Kenwright and the Goodison board for keeping all of the club's best players despite interest from a number of the Premier League's top sides.
He told Liverpool Echo: "The circumstances are what we are. Financially we're trying to keep all our best players and when you do that you have to invest in them. Look at eight of the players in the starting 11, they're on long term deals and that's expensive to do.
A lot of clubs sell their best players at the start of the season, or are struggling to keep them and we've kept ours this season.
"The transfer window isn't over and anything can happen, but we're footballers and not business men and we need to worry about playing well as a team and showing commitment. Hopefully we can still surprise people.
"There are positives. Our young players always play. One a year comes through and once again, the positive is we've kept our best players. If you sell four players to generate money that's one thing but we haven't - and then if you do buy players, are they going to improve the team?
"You see the way the market is going and how money is going throughout the world it's scarce and unless you've got crazy owners it's not going to happen.
"Everton prides itself on doing a few good deals, and it's not over yet. I'm optimistic and we could be the surprise package that saves the best to last. But if we don't buy we will probably but later on."