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 75 (VF), indicating a medium-low quality. This may influence the price, as coins in better condition tend to fetch higher prices.

2. Auction History:
- The average hammer price for similar coins in the past is 133.95 euros.
- Looking at the hammer prices of coins with a similar condition (75-80), prices have varied, but there are examples of auctions reaching up to 210 euros for conditions of 80 and 90.

3. Starting Price and Estimates:
- The starting price is 90 euros, and the estimated price is 150 euros. This suggests that there are expectations for the coin to sell for a price higher than the starting bid.

4. Recent Trends: In the most recent auctions, hammer prices have shown an increase, which could indicate a rising trend in interest for coins of this reference.

5. Comparison with Previous Prices:
- In previous auctions, coins with a condition of 75 have reached hammer prices of up to 160 euros.

Based on these factors, an estimated maximum purchase price for this coin could be around 160-180 euros, considering that interest in the coin may lead to a higher than expected hammer price. However, it is important to keep in mind that the final price will depend on the competition in the auction and the interest of collectors at that time.