Based on the provided data, we can observe that the coin has had an average auction closing price of 650 euros in previous auctions. Additionally, the current condition of the coin is graded at 75 (VF), indicating that it is not in the best condition but also not in the worst.

Considering that the starting price for the upcoming auction is 45 euros and the historical average starting price has been 100 euros, we could estimate that the closing price might fall within a similar range to the previous average closing price, around 650 euros.

Given that the current condition of the coin is graded at 75 (VF), which is relatively good but not excellent, and taking into account the prices of similar past auctions, we could estimate a maximum purchase price around 300-400 euros. This is considering that the coin will be auctioned in the coming days and the starting price is 45 euros.