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 75 (MBC), indicating that it is in fairly good shape, but not the best possible condition.

2. Auction History:
- The average hammer price for similar coins in the past is 896.41 euros.
- In previous auctions, coins with a similar condition (75) have reached hammer prices that vary, but some examples are:
- 550 euros (2020-07-02)
- 650 euros (2018-07-05)
- 720 euros (2020-10-27)
- 1200 euros (2022-10-19, although with a condition of 70)
- 2100 euros (2023-03-16, with a condition of 85)

3. Starting Price: The starting price is 700 euros, which may influence the final price, as the hammer price is often higher than the starting price.

4. Price Trends: Observing the trends, it seems there is an increase in hammer prices in recent auctions, especially for coins in good condition.

Based on these factors, an estimated maximum purchase price could be in the range of 900 to 1200 euros, considering that the average hammer price is 896.41 euros and there are examples of higher hammer prices for coins in similar conditions.

Therefore, a reasonable maximum purchase price could be 1200 euros.