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 80 (MBC+), indicating that it is in fairly good shape, but not the best possible condition (FDC).

2. Current Starting Price and Previous Prices: The current starting price is 1300 euros. In previous auctions, the average hammer price has been 1365.75 euros, suggesting that buyers are willing to pay a bit more than the starting price.

3. Price Trends: Looking at the hammer prices from previous auctions, it can be noted that coins with a similar condition have reached hammer prices that vary, but have occasionally exceeded 1500 euros, especially in higher conditions.

4. Comparison with Prices of Similar Condition: In recent auctions, coins with condition ratings of 80 have reached hammer prices of up to 1700 euros. However, the most common hammer price for similar conditions seems to be in the range of 1300 to 1500 euros.

5. Market Expectations: Given that there are no auctions scheduled in the coming days and considering historical demand, it is reasonable to assume that interest in this coin could be maintained.

Based on these factors, an estimated maximum purchase price for this coin could be around 1500 euros. This price reflects a balance between the current condition, previous hammer prices, and market trends.