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-). This is an important factor, as coins in better condition tend to reach higher prices.

2. Auction History:
- The average hammer price for similar coins has been 411.58 euros.
- In the past, coins with similar conditions (70) have sold for prices that varied considerably, but some relevant examples are:
- In 2018, a coin with a condition of 75 sold for 110 euros.
- In 2011, a coin with a condition of 90 sold for 350 euros.
- In 2013, a coin with a condition of 80 sold for 400 euros.

3. Starting Price: The starting price is 50 euros, indicating that the auctioneer expects interest in the coin.

4. Recent Trends: In the most recent auctions, hammer prices have shown a range that may indicate an increase in interest for coins of this reference.

Based on these factors, an estimated maximum purchase price could be in the range of 200 to 300 euros, considering that the condition is not the highest and that the price history shows significant variations.

Therefore, a reasonable maximum purchase price could be 250 euros.