To estimate a maximum purchase price for the coin in question, we can analyze the provided data, especially the previous auction prices and the current condition of the coin.

1. Current Condition: The coin has a condition of 70 (VF-). This indicates that it is in an acceptable state, but not of high quality.

2. Previous Auction Prices: By observing the auction prices of coins with similar conditions (70-75), we can see that:
- In previous auctions, coins with a condition of 70 have reached hammer prices of 150 to 225 euros.
- The last auction with a condition of 70 had a hammer price of 150 euros.

3. Average Hammer Price: The average hammer price for this coin is 258.72 euros, but this includes coins in better conditions.

4. Starting Price: The current starting price is 90 euros, which is relatively low compared to previous hammer prices.

5. Auction Trends: The coin has been auctioned 47 times, of which 44 have sold. This indicates good demand and consistent interest in the coin.

Based on these points, an estimated maximum purchase price could be in the range of 150 to 225 euros, considering that the condition is 70 and the starting price is 90 euros.

Therefore, a reasonable estimated maximum purchase price could be 200 euros. This allows for a margin for competition in the auction, given that the highest previous hammer price for a similar condition was 225 euros.

To estimate a maximum purchase price for the coin in question, we can analyze the provided data:

1. Condition: The coin has a condition of 70 (VF-), indicating that it is in quite good shape. This generally suggests that the final price could be higher than the average for coins in worse conditions.

2. Auction History:
- It has been auctioned 6 times in the past, of which it has sold 3 times.
- The average starting price is 9.83 euros, and the average final price is 8.67 euros.
- The starting and final prices in previous auctions varied, but there are examples where the starting price has been as high as 18 euros and the estimated price reached 30 euros.

3. Price Trends:
- In previous auctions, final prices have ranged between 9 and 14 euros, with an estimated price of up to 30 euros in one previous auction.
- Given that the coin has a condition of 70, it is reasonable to assume that it could achieve a final price higher than average.

4. Estimation:
- Considering the current starting price of 1 euro, which is quite low compared to previous starting prices, and the history of final prices, a reasonable maximum purchase price could be in the range of 15 to 20 euros, as this aligns with previous final prices for coins in similar conditions.

Therefore, an estimated maximum purchase price for this coin could be 20 euros.