To estimate a maximum purchase price for the coin in question, we can analyze the provided data and 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. Starting Price and Previous Prices: The current starting price is 90 euros. In previous auctions, the starting price has varied, but the average hammer price has been 162.44 euros. This suggests that, in general, coins of this reference tend to sell for a significantly higher price than their starting price.

3. Auction History: In previous auctions, we have seen hammer prices that varied depending on the condition. For example, in recent auctions, coins with a similar condition (70) have sold for prices ranging between 140 and 160 euros.

4. Price Trends: The average hammer price of 162.44 euros and the average starting price of 124.62 euros indicate a trend for coins to sell above their starting price.

5. Estimation Based on Historical Data: Given that the coin has a condition of 70 and considering previous hammer prices, an estimated maximum purchase price could be in a range between 150 and 180 euros, depending on the competition in the auction and the interest of collectors.

Conclusion: Based on the analysis, an estimated maximum purchase price for this coin could be approximately 170 euros. This is based on the history of hammer prices and the current condition of the coin.