To estimate a maximum purchase price for the coin in question, we can consider several factors based on the provided data:

1. Current Condition: The coin has a condition of 70 (VF-). This is an important factor, as coins in better condition tend to reach higher prices.

2. Starting Price and Average Hammer Price: The current starting price is 75 euros, and the average hammer price in previous auctions is 164.23 euros. This suggests that, in general, coins of this reference tend to sell for a significantly higher price than their starting price.

3. Auction History: In the auction history, there have been variations in hammer prices. For example, in 2014, a coin with a similar condition was sold for 110 euros, and in 2018, a coin of the same reference was sold for 210 euros. This indicates that there is a considerable range in hammer prices.

4. Recent Trends: In the most recent auction of 2022, the coin was sold for 75 euros, which matches the current starting price. However, in previous auctions, higher prices have been reached, suggesting that there could be potential for an increase in the hammer price.

Taking all these factors into account, an estimated maximum purchase price could be in the range of 150 to 200 euros, considering that the condition is a limiting factor and that the price history shows that similar coins have reached higher prices in the past.

Therefore, a reasonable maximum purchase price could be 180 euros.