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:
- In previous auctions, the coin has had hammer prices that vary significantly. For example:
- A hammer price of 220 euros with a condition of 95.
- A hammer price of 35 euros with a condition of 80.
- A hammer price of 20 euros with a condition of 70.
- A hammer price of 50 euros with a condition of 75.

3. Price Trends:
- The average hammer price for this coin is 69 euros, suggesting that, in general, buyers are willing to pay around this amount.
- The average starting price is 42 euros, indicating that auctioneers usually start with lower prices.

4. Condition Analysis:
- Given that the coin's condition is 70, we can expect its hammer price to be closer to the hammer prices of previous coins with similar conditions. For example, the hammer price of 20 euros and the hammer price of 50 euros are relevant examples.

5. Maximum Price Estimation:
- Considering all these factors, a reasonable maximum purchase price could be in the range of 50 to 70 euros, as this price reflects both the current condition and the previous hammer prices.

Therefore, an estimated maximum purchase price for this coin could be 70 euros.