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

1. Current Condition: The coin has a condition of 30 (BC+), which indicates that it is not in very good shape. This will negatively affect its value compared to coins in better condition.

2. Auction History:
- It has been auctioned 7 times in the past, of which 6 have sold. This indicates a consistent interest in the coin.
- The average hammer price in previous auctions is 162.5 euros, suggesting that, in general, buyers are willing to pay more than the starting price.

3. Previous Auction Prices:
- In the 2022 auctions, it was observed that coins with a condition of 70 and 75 sold for prices ranging from 150 to 260 euros. However, the condition of the current coin is significantly lower (30), suggesting that its value will be much less.

4. Starting Price and Average Starting Price:
- The current starting price is 80 euros, and the average starting price in the past has been 97.14 euros. This indicates that the current starting price is reasonable, but it also suggests that there could be room for a higher hammer price.

Taking all these factors into account, an estimated maximum purchase price for this coin could be in the range of 100 to 120 euros. This is based on the historical interest in the coin, the average hammer price, and the current condition, which limits its value.