The Bundesliga side are reportedly demanding at least €120 million for the 20-year-old France international.
With Barcelona currently looking to reinvest the €222 million world-record transfer fee they received for Neymar last week, Dembele has been one of the prime targets for the La Liga giants.
Addressing the persistent rumours at the weekend, Dortmund CEO Hans-Joachim Watzke said that a rumoured transfer of around €100 million would not be enough for the France international, who has four years left on his deal at the Westfalenstadion.
But Dortmund have now named the price for Dembele, with reputable news outlets reporting that Dortmund would be willing to let go of their winger should Barcelona make a bid in the region of €120 million.
Reports also noted that Dembele had removed any mention of Dortmund from his social media accounts.
Earlier on Tuesday, reports from Spain emerged saying that a three-piece Barcelona delegation, including football management director Raul Sanllehi, is set for a trip to Dortmund to enter negotiations with the Bundesliga side.
ESPN Brasil sources said the delegation had flown to Liverpool on Monday night to seek another high-priced transfer for Philippe Coutinho, with sources telling ESPN Deportes that a deal had been agreed.
Having joined Dortmund on a €15 million transfer from Stade Rennes last summer, Dembele soon made a name for himself in Germany and Europe.
The winger was directly involved in 31 goals, scoring 10 and setting up a further 21, the majority of them when linking up with Bundesliga top scorer Pierre-Emerick Aubameyang.
Stephan Uersfeld is the Germany correspondent for ESPN FC. Follow him on Twitter @uersfeld.