To estimate a maximum purchase price for the coin in question, we can analyze the provided data, especially considering the current condition of the coin (80, MBC+) and previous auction prices.

1. Condition: The coin has a condition of 80 (MBC+), indicating that it is in quite good shape. This suggests that its value should be in the upper range of previous auction prices for coins with a similar condition.

2. Previous auction prices:
- In previous auctions, we have seen hammer prices that vary considerably. For example:
- In 2018, a coin with a condition of 80 was auctioned for 116 euros.
- In 2022, a coin with a condition of 70 was auctioned for 180 euros.
- In 2022, another coin with a condition of 80 was auctioned for 110 euros.
- In 2024, a coin with a condition of 80 was auctioned for 260 euros.

3. Average hammer price: The average hammer price for this coin is 153.59 euros, which is also a good indicator of the expected value.

4. Starting price: The starting price is 140 euros, which is reasonable given the price history.

Based on this data, an estimated maximum purchase price could be in the range of 200 to 260 euros, considering that the condition is good and there are precedents for auctions in that range. However, since the starting price is 140 euros, it is likely that the hammer price will not significantly exceed this value.

Therefore, an estimated maximum purchase price could be approximately 220 euros. This allows for some competition in the auction, but it is also based on the historical auction prices for coins in similar conditions.