Found 3 exchanges where Kusama is traded for EUR. According to the data on 28 August the most optimal price to exchange KSM for EUR is €3.05 for 1 Kusama. This rate is fixed at Bit2Me at the maximum trading volume of the pair KSM/EUR - 61 ths. EUR.
The maximum daily trading volume is observed in the KSM/USDT trading pair at BitDelta and reaches € 8 975 535.64 (0.487% of the exchange's total trading volumes) at the price € 2.98 per 1 KSM.
The minimum price to buy KSM for EUR is 3.01 - on the exchange Bitvavo.
The maximum price to buy KSM/EUR is 3.23 - on the exchange Kraken.