Borussia Dortmund CEO Hans-Joachim Watzke has said his club would be ready to spend a €100 million transfer fee on a single player -- but prefer other methods of building a team.
"Players in the top-shelf no longer cost €50m but rather €100m," Watzke told Sportbild, adding: "We could also muster that if we absolutely want a player and of whom we are convinced 1,000 percent.
"But to be honest, we'd rather mould such a player ourselves. BVB were always at their strongest when we could develop our own stars."
Germany international Andre Schurrle was Dortmund's most expensive purchase at €30m when he arrived from Wolfsburg in 2016, but the 27-year-old has not found his feet at the Westfalenstadion and is reportedly close to signing a two-year loan with Premier League side Fulham, as the Black and Yellows are looking to clear their wage bill.
Watzke also said it's important to consider the potential resale value of a player when considering transfer fees in the current market.
"The transfer fee itself does not have any significance nowadays anymore," he said. "When it comes to deals in such dimensions it's about the whole bundle. You have to take your focus away from the transfer fee and analyse a player under sporting and economical aspects.
"If I invest €100m in a player that's older than 30, the €100m will be gone. You will not be able to sell that player later.
"If I -- to name a fictional example -- could have signed [19-year-old] Kylian Mbappe for €100m then I had done it immediately. The chance to sell him at a profit further down the road would be quite big."
Asked which player he would purchase if he had unlimited funds, Watzke named former Dortmund striker Robert Lewandowski but he immediately shot down any possibility his club could sign him from Bayern Munich.
"Robert's return is completely unrealistic we don't have to waste any thoughts to that," Watzke said.
Dortmund have been a frequent name to appear in recent transfer rumours, however.
Belgium newspaper Het Laatste Nieuws reported that BVB have offered €20m for Belgium international Axel Witsel. The 29-year-old holding midfielder playing for Chinese club Tianjin Quanjian has said he wants to return to Europe and could bolster Dortmund's midfield as midfielder Julian Weigl continues to struggle with abductor injury that may rule him out for the start of the 2018-19 season.
The Ruhr Side are also on the outlook for a new centre-forward to fill the void left by Michy Batshuayi, who was on a six-month loan from Chelsea, but have described links to Juventus' Mario Mandzukic and Chelsea's Alvaro Morata as unfeasible at the moment.