The Belgian midfielder was finally confirmed as a Claret on Tuesday, on a three-year deal, with an option for another 12 months, signing for €8.5m, or roughly £7.4m, from Anderlecht.
That topped the £6m paid for Andre Gray last August, and asked if the club will break the record again before the transfer window closes, Dyche said: “We’ll see. The market is unforgiving – you either get in it or you don’t.
“But the key is trying to get quality that can move you forward, and that costs.
“There are players out there you wouldn’t consider being worthy of a certain amount, but that’s the market.
“The £37.5m we paid for Andre looks cheap now!
“It’s incredibly how quickly the market changes, and how high is is going.
“We’re still in the market and looking to do many things, but often Championship players are earning more than they can earn in the Premier League.”
The Defour signing is a real statement of intent, however, and Dyche explained how it came about: “He’s a player we’ve been scouting quite heavily last season and going into the summer, and there was a whisper he might be available.
“You never know quite how that builds from there, but the thirst was there from the player to play in the Premier League, with his background of playing across Europe, and for Belgium in one of their best eras, so many are playing over here now, and the idea appealed. It was a tough deal to do, but we hope it will be worthwhile.”
And will Defour be in line to make his debut at home to Liverpool tomorrow?: “He has got to adapt – we’ve seen him play Belgian football, which is slower, more technical and tactical, and there will be a period where he adapts.
“But he is a bright player, he knows the game tactically and at different levels.
“He will figure out where he is at physically, in terms of the Premier League. He is physically sound – he’s played four games this season already – but the Premier League is different, a different tempo, and pace.
“The key for a player is to be ready to perform – it’s a much tougher proposition to perform to be ready.
“You have to have a base idea of the way the team performs, and we’ll decide over the next day or so. But I’ve spoken to him, he’s bright, and he’s aware of how the game differs here. He played against Spurs last season.”
While Dyche decides the best course of action for Defour, he is again expected to be without striker Ashley Barnes after a hamstring problem: “He’s back on the grass, but I doubt he’ll be ready. Hopefully it is settling down and strengthening now.”