To estimate a maximum purchase price for the coin in question, we can analyze the provided data, especially the condition, previous auction prices, and the average auction price.

1. Condition: The coin has a condition of 80 (VF+), indicating that it is in quite good shape.

2. Previous auction prices:
- In previous auctions, coins with a similar condition (80) have had auction prices that vary, but some examples are:
- 2023-01-18: 170 euros
- 2022-10-19: 240 euros
- 2022-02-17: 115 euros
- 2022-04-27: 115 euros

3. Average auction price: The average auction price for this coin is 122.63 euros, which is also a good indicator.

4. Starting price: The starting price is 75 euros, which is reasonable and may attract bidders.

Given that the condition is good and previous auction prices have reached significant figures, an estimated maximum purchase price could be in the range of 170 to 240 euros, based on the highest previous auctions.

Final estimation: A reasonable maximum purchase price could be 200 euros. This is based on the trend of previous auction prices and the current condition of the coin.