Based on the data provided, we can observe that the coin has had an average auction closing price of 19.8 euros in previous auctions. Additionally, its current condition is 30 (BC+).

Considering that the coin has been auctioned 42 times in the past and sold in 32 of those auctions, we can see that it has a relatively stable demand in the auction market.

Given that the coin will be auctioned in the upcoming days with a starting price of 30 euros, and taking into account its previous price history, condition, and demand in previous auctions, we could estimate a maximum purchase price around 25-30 euros.

It is important to note that the final auction price may vary depending on factors such as competition from other bidders, the exact condition of the coin, and other elements that may influence collectors' valuation.