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:
- It has been auctioned 6 times in the past, of which 5 have sold. This indicates a consistent interest in the coin.
- The average starting price in previous auctions is 365.25 euros, and the average hammer price is 1137.57 euros. This suggests that, although the current starting price is 60 euros, the actual value of the coin may be significantly higher.

3. Previous Prices:
- Previous hammer prices varied considerably, with a maximum price of 3684.58 euros for a coin in condition 107.
- The last auction in 2017 reached a hammer price of 1200 euros, although the condition is not specified.

4. Market Trends: Given that the current starting price is 60 euros, which is significantly lower than the average starting and hammer prices, this could indicate a buying opportunity.

Based on these factors, an estimated maximum purchase price could be in the range of 300 to 600 euros, considering that the coin's condition is 70 and that interest in it has been consistent in the past. This allows for a margin for potential appreciation in value in future auctions.

Therefore, a reasonable maximum purchase price could be 500 euros.