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

1. Coin Condition: The coin has a condition rating of 30 (BC+), indicating that it is not in the best condition. This will affect its value compared to coins in better condition.

2. Auction History:
- The average hammer price for similar coins in the past has been 89.22 euros.
- In previous auctions, coins with a similar condition (30) have had hammer prices that varied, but the highest recorded price for a coin with a condition of 30 was 60 euros.

3. Starting Price and Recent Hammer Prices:
- The current starting price is 40 euros, which is reasonable given the history of starting and hammer prices.
- In recent auctions, the hammer price for coins with similar conditions has ranged from 41 to 60 euros.

4. Market Trends: Given that there are 2 auctions scheduled in the coming days, this may increase competition and potentially the hammer price.

Based on these factors, an estimated maximum purchase price for this coin could be around 60-70 euros. This is based on the hammer price history for coins with a similar condition and the current market context.