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

1. Condition: The coin has a condition of 80 (MS+), indicating that it is in relatively good shape, but not of the highest quality (PRF).

2. Auction History:
- The average hammer price for similar coins has been 171.34 euros.
- In previous auctions, coins with similar conditions (80-85) have reached hammer prices that varied, but some examples are:
- 2022-07-07: 70 euros (condition 80)
- 2022-06-01: 240 euros (condition 95)
- 2023-03-16: 150 euros (condition 90)
- 2020-02-12: 55 euros (condition 85)

3. Price Trends:
- The current starting price is 15 euros, which is quite low compared to the average hammer price.
- The coin has been auctioned 75 times, with a high sales percentage (70 out of 75), indicating good demand.

4. Comparison with Previous Prices:
- The coin has had hammer prices that vary significantly, but the range seems to be between 55 and 550 euros, depending on the condition and demand at the time of the auction.

Based on these factors, an estimated maximum purchase price for this coin could be in the range of 150 to 250 euros. This range takes into account the current condition, the auction price history, and the general trend in the market.