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

1. Condition: The coin has a condition rating of 100 (MS), indicating that it is in excellent condition. This generally translates to a higher price compared to coins with lower conditions.

2. Auction history:
- The average hammer price for this coin in the past is 183.6 euros.
- The average starting price is 120.76 euros.
- In previous auctions, hammer prices have varied, but there are examples of sales reaching up to 180 euros in similar conditions.

3. Recent trends: In the most recent auctions, hammer prices have been around 180 euros for coins in similar conditions. This suggests that interest and value for the coin are on the rise.

4. Supply and demand: The coin has been auctioned 38 times, of which it has sold 27 times. This indicates good demand, which can influence the price.

Based on these factors, an estimated maximum purchase price for this coin could be around 200 euros. This is based on the auction price history and the excellent condition of the coin. However, it is important to consider that the final price may vary depending on competition in the auction and other market factors at the time of sale.