To estimate a maximum purchase price for the coin that will be auctioned, we can analyze the provided data. Here are some key points to consider:

1. Starting price: 120 euros.
2. Average hammer price: 146.02 euros.
3. Auction history: The coin has been auctioned 75 times, of which it has sold 68 times. This indicates good demand.
4. Previous prices: Hammer prices in previous auctions have varied, but there are several examples where the hammer price has exceeded 150 euros, even reaching 270 euros in a recent auction.

Since the condition of this coin is not specified, it is difficult to make a direct comparison with previous auctions. However, we can observe that in previous auctions, coins with a condition of 95 have had hammer prices ranging from 130 to 270 euros.

### Estimation of the maximum purchase price:
- Based on the average hammer price: 146.02 euros.
- Considering the highest hammer price in history: 270 euros.
- Taking into account the starting price: 120 euros.

Given that the starting price is 120 euros and considering that the average hammer price is 146.02 euros, a reasonable maximum purchase price could be between the average hammer price and the highest hammer price.

### Estimated maximum purchase price:
Between 160 and 200 euros.

This allows for a margin for competition in the auction, considering that the hammer price may be higher depending on the demand and the condition of the coin.