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 70 (VF-), indicating that it is in relatively good shape, but not of the highest quality. This may influence the price, as coins in better condition tend to fetch higher prices.

2. Auction History:
- The coin has been auctioned 7 times in the past, of which it has sold 5 times. This indicates an interest in the coin, which may increase its value.
- The average starting price in previous auctions is 75.86 euros, and the average hammer price is 149.36 euros. This suggests that, in general, coins of this reference tend to sell for significantly higher prices than their starting price.

3. Previous Prices:
- In 2012, the coin sold for 160 euros with a condition of 90.
- In 2015, it sold for 201.78 euros, although the condition is not specified.
- In 2019, it sold for 120 euros with a condition of 80.
- In 2021, it sold for 200 euros with a condition of 85.

4. Price Trends: The hammer prices have shown a range from 65 euros to 201.78 euros, depending on the condition. The trend seems to be that as the condition improves, the hammer price also increases.

Given that the condition of the coin in question is 70 (VF-), and considering the price history and average hammer price, an estimated maximum purchase price could be in the range of 100 to 130 euros. This is based on the fact that, although the condition is not the best, the interest in the coin and the price history suggest that it could reach a reasonable price at auction.

Therefore, an estimated maximum purchase price could be 120 euros.