To estimate a maximum purchase price for the coin in question, we can analyze the provided data:

1. Current Condition: The coin is in condition 100 (MS), indicating that it is in excellent shape. This generally increases its value compared to coins in lower conditions.

2. Auction History:
- The average hammer price in previous auctions is 34.14 euros.
- The highest recorded auction price was 110 euros, although that coin had a condition of 85.
- The most recent auction with a condition of 95 had a hammer price of 45 euros.

3. Starting Price: The current starting price is 15 euros, which is relatively low compared to the average hammer price.

4. Price Trends: Looking at previous hammer prices, it seems that coins in good condition (95 or higher) tend to sell for over 30 euros, and the coin in MS condition (100) should attract a higher price.

Based on this data, an estimated maximum purchase price could be between 50 and 70 euros, considering that the condition is excellent and that the auction history shows similar coins have reached higher prices. Therefore, a reasonable maximum purchase price could be 65 euros.