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

1. Current condition: The coin has a condition of 80 (MBC+), which indicates that it is in fairly good shape, although it is not the best possible condition.

2. Previous prices:
- In 2011, a coin with a condition of 90 sold for 170 euros and 115 euros at different auctions.
- In 2014, another coin with unspecified condition (but likely similar) sold for 130 euros.

3. Average hammer price: The average hammer price for this coin is 120 euros, suggesting that, in general, coins of this reference tend to sell around this price.

4. Starting price: The starting price is 60 euros, which may attract more bidders, but does not necessarily indicate the final hammer price.

Given that the condition of the coin is 80 (MBC+), which is lower than the conditions of 90 that have sold in the past, it is reasonable to adjust the estimated price downward compared to previous hammer prices.

Taking all these factors into account, an estimated maximum purchase price could be around 100-110 euros. This is based on the fact that, although the condition is good, it is not the best, and the average hammer price suggests that there could be competition, but not at the level of the higher conditions.