To estimate a maximum purchase price for the coin in question, we will consider several factors:

1. Condition: The coin has a condition rating of 85 (ebc-), which is quite good. In the past, coins with this condition have reached auction prices of up to 232.93 euros.

2. Previous auction prices: Previous auction prices for coins with the same condition (85) have been:
- 140.38 euros (2011)
- 232.93 euros (2011)
- 190 euros (2016, estimated price)
- Other auction prices for lower conditions (75) have been significantly lower.

3. Average auction price: The average auction price for this coin is 187.37 euros, indicating that, in general, coins of this reference tend to sell for above 160 euros.

4. Starting price: The current starting price is 70 euros, suggesting that there is considerable room for the auction price to be higher.

5. Sales history: The coin has been auctioned 11 times, of which it has sold 8 times, indicating good demand.

Taking all these factors into account, an estimated maximum purchase price could be in the range of 200 to 250 euros, considering that the highest auction price in the past was 232.93 euros and that the current condition is favorable. Therefore, a reasonable maximum purchase price could be approximately 220 euros.