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

1. Current Condition: The coin has a condition of 80 (MS+), indicating that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Previous Auction Prices: By observing previous auction prices of coins with similar conditions (around 80), we can see that prices have varied. For example, in past auctions, coins with a condition of 80 have reached hammer prices of up to 150 euros.

3. Average Hammer Price: The average hammer price for this coin is 136.65 euros, providing a good reference point.

4. Recent Trends: In the most recent auctions, hammer prices have shown a range that can go from 90 to 700 euros, depending on the condition and demand at the time of the auction.

5. Starting Price: The starting price is 110 euros, indicating that the seller expects a reasonable minimum price.

Taking all these factors into account, an estimated maximum purchase price for this coin could be around 180-200 euros. This is based on the current condition, previous hammer prices, and market trends. However, it is important to remember that the final price may vary depending on the competition in the auction and the specific demand at that time.