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

1. Current Condition: The coin has a condition rating of 75 (MBC), indicating that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Auction History:
- The coin has been auctioned 6 times, of which it has sold 5 times. This indicates a consistent interest in the coin.
- The average hammer price in previous auctions is 106 euros, providing a good benchmark.
- In the most recent auction (2022), the coin sold for 220 euros, suggesting there is potential for a high price, especially if the condition is good.

3. Starting Price and Average Starting Price:
- The current starting price is 30 euros, which is significantly lower than the average starting price of 70.83 euros. This could indicate a buying opportunity.

4. Price Trends:
- Previous hammer prices varied, but the highest was 220 euros in 2022. This suggests that, although the starting price is low, interest in the coin may lead to a higher hammer price.

Based on these factors, an estimated maximum purchase price could be in the range of 150 to 220 euros, considering that the condition is good and there is a history of high prices in previous auctions. A price of 200 euros could be a reasonable target, as it falls in the middle of this range and reflects both the interest in the coin and its condition.