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

1. Current Condition: The coin has a condition rating of 75 (VF), indicating that it is in fairly good shape, but not among the best qualities.

2. Auction History:
- The average hammer price for similar coins has been 153.72 euros.
- In previous auctions, coins with similar conditions (around 75) have had hammer prices that varied, but some examples are:
- 2023-05-24: Hammer price 140 euros (condition 80).
- 2023-01-18: Hammer price 95 euros (condition 70).
- 2022-10-17: Hammer price 100 euros (condition 85).

3. Starting Price and Average Starting Price:
- The current starting price is 45 euros, which is quite low compared to the average hammer price.
- The average starting price for similar coins is 93.53 euros.

4. Sales Trends: The coin has been auctioned 52 times, of which 49 have been sold, indicating good demand.

Based on these factors, an estimated maximum purchase price could be between 120 and 160 euros, considering that the condition is good and that the hammer price history for similar coins supports this estimate.

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