To estimate a maximum purchase price for the coin in question, we will consider several factors:

1. Current Condition: The coin has a condition of 75 (MBC), which indicates that it is in quite good shape. This may positively influence its price.

2. Auction History:
- The average hammer price in previous auctions is 154.36 euros.
- In past auctions, hammer prices have varied, with some reaching up to 280 euros in a recent auction (2023-01-18) for a coin with a condition of 80.
- Most coins with similar conditions (70-80) have had hammer prices ranging between 110 and 180 euros.

3. Starting Price and Estimates:
- The current starting price is 110 euros, which is a good starting point.
- The estimated hammer price for this auction is 150 euros, which is also consistent with the price history.

4. Demand and Supply: Since there have been no unsold coins of this reference in the past, this suggests that there is a steady demand.

Based on these factors, an estimated maximum purchase price could be in the range of 180 to 220 euros, considering that the condition is good and that the price history shows that similar coins have reached higher prices in the past.

Therefore, a reasonable maximum purchase price could be 200 euros.