To estimate a maximum purchase price for the coin that will be auctioned, we can consider several factors based on the provided data:

1. Coin Condition: The coin has a condition rating of 95 (S/C-), indicating that it is in very good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Starting Price and Previous Prices: The current starting price is 1200 euros. In previous auctions, we have seen hammer prices that vary, but there are examples of hammer prices exceeding 1800 euros for coins with similar conditions.

3. Price Trends: The average hammer price for similar coins is 1282.04 euros, suggesting that the market is willing to pay a bit more than the starting price in many cases.

4. Auction History: In the past, coins with conditions of 90 and 95 have reached hammer prices ranging from 1400 to 2200 euros, depending on demand and other market factors.

Based on these points, an estimated maximum purchase price could be in the range of 1800 to 2200 euros, considering that the condition is high and that interest in the coin may be significant.

Therefore, a reasonable maximum purchase price could be 2000 euros. This allows for some margin for competition in the auction, given that the hammer price may exceed the starting price.