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

1. Current Condition: The coin has a condition rating of 70 (MBC-), which indicates that it is in acceptable shape, but not in the best condition. This can influence the price, as coins in better condition tend to fetch higher prices.

2. Auction History:
- The average hammer price for similar coins in the past has been 118.62 euros.
- The coin has been auctioned 14 times, of which it has sold 13 times, indicating good demand.
- Previous hammer prices for coins with similar conditions (70 and 75) have varied, but some have reached up to 210 euros in a 2022 auction.

3. Starting Price and Average Starting Price:
- The current starting price is 40 euros, and the average starting price in the past has been 51.2 euros. This suggests that the current starting price is reasonable and could attract bidders.

4. Price Trends:
- In previous auctions, hammer prices have ranged from 23 to 600 euros, depending on the condition and other factors. However, the highest prices have been for coins in better condition.

Based on these factors, an estimated maximum purchase price could be in the range of 100 to 150 euros, considering that the condition is 70 and there is a history of hammer prices that supports this estimate.

Therefore, a reasonable maximum purchase price could be 150 euros.