To estimate a maximum purchase price for the coin in question, we can consider several factors based on the provided data:

1. Coin Condition: The coin has a condition rating of 80 (MBC+), indicating that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Average Hammer Price: The average hammer price for similar coins is 99.8 euros. This suggests that, on average, coins of this reference sell for a price close to this value.

3. Auction History: Looking at previous hammer prices, there are several examples of coins with similar conditions that have sold for varying prices, with some reaching hammer prices of up to 360 euros (as seen in the auction on 2018-10-17).

4. Starting Price: The starting price of 60 euros is a good starting point, but given the history of hammer prices, it is likely that the final selling price will be significantly higher.

5. Recent Trends: In the most recent auctions, hammer prices have shown a trend of being higher, especially for coins in good condition.

Taking all these factors into account, an estimated maximum purchase price could be in the range of 150 to 200 euros. This is based on the history of hammer prices and the condition of the coin, suggesting that it could attract collectors willing to pay a premium price for a coin in good condition.