To estimate a maximum purchase price for the coin in question, we can consider several factors based on the provided data:

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 305.15 euros.
- In the past, coins with similar conditions (around 70-75) have been auctioned and reached hammer prices that varied, but some examples are:
- 2013-04-19: 164.51 euros (condition 75)
- 2013-06-15: 64.72 euros (condition 75)
- 2022-06-09: Not sold, but the condition was 70.
- 2022-07-07: 360 euros (condition 80)
- 2023-03-01: 230 euros (condition 85)

3. Starting Price: The starting price is 200 euros, indicating that the seller expects a minimum of 200 euros.

4. Price Trends: Observing the hammer prices of coins with similar conditions, it seems that the price range can vary quite a bit, but there are examples of coins that have reached hammer prices above 300 euros.

Based on these factors, an estimated maximum purchase price could be in the range of 250 to 350 euros, considering that the condition is slightly lower than that of some coins that have reached higher prices, but still, the auction history suggests there may be interest in paying a reasonable price for a coin in VF- condition.

Therefore, an estimated maximum purchase price could be approximately 300 euros.