Found 2 exchanges where ZKsync is traded for EUR. According to the data on 31 August the most optimal price to exchange ZK for EUR is €0.0082 for 1 ZKsync. This rate is fixed at Bitvavo at the maximum trading volume of the pair ZK/EUR - 568.2 ths. EUR.
The maximum daily trading volume is observed in the ZK/KRW trading pair at Upbit and reaches € 7 844 703.98 (1.34% of the exchange's total trading volumes) at the price € 0.0081 per 1 ZK.
The minimum price to buy ZK for EUR is 0.0078 - on the exchange Bit2Me.
The maximum price to buy ZK/EUR is 0.0082 - on the exchange Bitvavo.
Warning: some ZK markets show an abnormally wide spread — those quotes may be unreliable (thin liquidity or off-market trades). Cross-check the volume against several venues.